Verification: Written agreement between the air taxi Operator and the major command Or an installation commander (AFM 75–2, Military Traffic Management Regulation, paragraph 304010). Verification: Active duty Air Force serial number, and for personnel of the other Services, provide proof of active duty Status. Tabtight professional, free when you need it, VPN service.
Operational range 480 km (300 mi) Speed 67.6 km/h (42.0 mph), 5.8 km/h (3.6 mph) swimming The M113 is a fully tracked that was developed by (FMC). The vehicle was first fielded by the 's units in Vietnam in April 1962.
The M113 was the most widely used armored vehicle of the U.S. Army in the, earning the nickname 'Green Dragon' by the as it was used to break through heavy thickets in the midst of the jungle to attack and overrun enemy positions. It was largely known as an 'APC' or an 'ACAV' ( assault vehicle) by the allied forces. The M113 introduced new aluminum armor that made the vehicle much lighter than earlier vehicles; it was thick enough to protect the crew and passengers against small arms fire but light enough that the vehicle was air transportable and moderately amphibious.
Army, the M113 series have long been replaced as front-line combat vehicles by the M2 and M3, but large numbers are still used in support roles such as armored ambulance, mortar carrier, engineer vehicle, and command vehicle. The army's heavy brigade combat teams are equipped with around 6,000 M113s and 4,000 Bradleys. The M113's versatility spawned a that live on worldwide, and in U.S. These variants together currently represent about half of U.S.
Army armored vehicles. To date, it is estimated that over 80,000 M113s of all types have been produced and used by over 50 countries worldwide, making it one of the most widely used of all time. The Military Channel's Top Ten series named the M113 the most significant infantry vehicle in history. Army planned to retire the M113 family of vehicles by 2018, seeking replacement with the program, but now replacement of the M113 has fallen to the (AMPV) program. Thousands of M113s continue to see combat service in the, although as of 2014 the IDF was seeking to gradually replace many of its vehicles with.
FMC T117 proposal The M113 was developed by (FMC), which had produced the earlier and Armored personnel carriers. The M113 bears a very strong resemblance to both of these earlier vehicles. The M75 was too heavy and expensive to be useful; its weight prevented amphibious capability, and being transported by air. The lightened M59 addressed both of these problems, but ended up with too little armor, and was unreliable as a result of efforts to reduce its cost. The army was looking for a vehicle that combined the best features of both designs, the 'airborne armored multi-purpose vehicle family' (AAM-PVF). Of all-purpose, all-terrain armored fighting vehicles FMC had been working with in the late 1950s to develop suitable aluminum armor.
It was known that use of this armor could produce a vehicle that provided the protection of the M75, and the light weight and mobility of the M59. Food Machinery Corp. Responded with two proposals; two versions of the aluminum T113—a thicker and a thinner armored one—along with the similar but mostly steel T117. The thicker-armored version of the T113, effectively the prototype of the M113, was chosen because it weighed less than its steel competitor, while offering the same level of protection. An improved T113 design, the T113E1, was adopted by the U.S. Army in 1960 as the 'M113'.
A diesel prototype, T113E2, was put into production in 1964 as the 'M113A1', and quickly supplanted the gasoline-engined M113. In 1994, FMC transferred the M113's production over to its newly formed defense subsidiary,. Then in 2005, United Defense was acquired.
Army soldiers dismount from an M113 armored personnel carrier during a training exercise in September 1985 The M113 was developed to provide a survivable and reliable light tracked vehicle able to be air-lifted and air-dropped, by and transport planes. The original concept was that the vehicle would be used solely for transportation, bringing the troops forward under armor and then having them dismount for combat; the M113 would then retreat to the rear. Entering service with the U.S. Army in 1960, the M113 required only two crewmen, a driver and a commander, and carried 11 passengers inside the vehicle. Its main armament was a single.50-caliber (12.7 mm) operated by the commander. On 30 March 1962, the first batch of 32 M113s arrived in Vietnam, and were sent to two (ARVN) mechanized rifle companies, each equipped with 15 of the APCs.
On 11 June 1962, the two mechanized units were fielded for the first time. During the in January 1963, at least fourteen of the exposed.50 caliber gunners aboard the M113s were killed in action, necessitating modifications to improve crew survivability. Soon, makeshift shields formed from metal salvaged from the hulls of sunken ships were fitted to the carriers, which afforded better protection. But, finding that this material could be penetrated by small arms fire, subsequent shields were constructed from scrapped armored vehicles. The ARVN 80th Ordnance Unit in South Vietnam developed the shield idea further and commenced engineering general issue gun shields for the M113.
These shields became the predecessor to the standardized armored cavalry assault vehicle (or ACAV) variant and were issued to all ARVN mechanized units during the early 1960s. The ARVNs had modified the M113s to function as ' ' and not as battle taxis as U.S. Designers had intended.
Instead of an armored personnel carrier, the ARVN used the carried infantry as extra 'dismountable soldiers' in 'an over-sized tank crew'. These 'ACAV' sets were eventually adapted to U.S.
Army M113s with the arrival of the army's conventional forces in 1965. The vehicles continued to operate in the role of a light tank and reconnaissance vehicle, and not as designed in theater. Still, the M113 could carry 11 infantrymen inside, with two crewmen operating it.
Interior of an M113 at the American Armored Foundation Museum in Danville, Virginia, July 2006 The U.S. Army, after berating the Vietnamese for flouting battle doctrine, came out with their own ACAV version. This more or less standardized ACAV kit included shields and a circular turret for the.50-caliber M2 machine gun in the track commander (TC) position, two M60 machine guns with shields for the left and right rear positions, and 'belly armor'—steel armor bolted from the front bottom extending 1/2 to 2/3 of the way towards the bottom rear of the M113. The two rear machine gunners could fire their weapons while standing inside the rectangular open cargo hatch. This transformed the M113 into a fighting vehicle, but the vehicle still suffered from its lightly armored configuration, having never been designed for such a role. Canada also adopted the ACAV kits when employing the M113A2 during peacekeeping operations in the Balkans in the 1990s.
In order to improve the fighting ability of the mounted troops, a number of experiments were carried out in the 1960s under the project, which aimed to develop a true infantry fighting vehicle rather than an armored personnel carrier. Entered the steel-armored XM701, but this proved to be too slow and too heavy to be airmobile, even in the C-141. Food Machinery Corp.
Entered the XM734, which was largely the ACAV M113, but whereas the M113 seated the troops facing inward on benches along the walls, the XM734 sat them facing outwards on a central bench. Four gun ports and vision blocks were added on each side to allow the seated troops to fire even while under cover. Although neither the XM701 or XM734 were deemed worthwhile to produce, FMC continued development of their version as the (AIFV). The AIFV was sold to a number of third party-users in the 1970s, including the Netherlands, the Philippines and Belgium. Modifications [ ]. A M113 at, Iraq, Nov 16, 2008. The vehicle was a part of the 532nd Expeditionary Security Forces Squadron's immediate response forces (IRF) and equipped with and an Modified versions of the Vietnam War ACAV sets have been deployed to Iraq (formerly referred to as 'Southwest Asia' within the U.S.
Military) to equip the standard M113s still in service. The circular.50 caliber gun shields have been modified, while the rear port and starboard gun stations have been deleted for service in that region.
Some of these modified vehicles have been utilized for convoy escort duties. The M113 has relatively light armor, but it can be augmented with add-on steel plates for improved ballistic protection. Also, and can be added for protection against. Developed by an armorer in Iraq is reminiscent of ACAV vehicle modifications so effective in Southeast Asia (Vietnam War). Made of rubber are in use by Canadian and other forces to enable stealthy operation, less damage to paved roads, higher speed, less maintenance, access to terrain where operation of wheeled vehicles is impractical and less vibration and rolling resistance. Most of the 13,000 M113s that are still in U.S.
Army service have been upgraded to the A3 variant. The M113 has also been adopted to replace the aging fleet of being used to simulate Russian-made combat vehicles at the U.S. Army's in Fort Irwin, California. These M113s, like the M551s they replaced, have also been modified to resemble enemy tanks and APCs, such as the and.
One of the advantages of the M113 being used to simulate the latter is that the infantry squad can now ride inside the simulated BMP instead of in a truck accompanying a tank masquerading as one, as was often the case with the M551s. Nicknames [ ] The M113 has received a variety of nicknames over the years. The South Vietnamese Army () called it the 'green dragon'.
United States troops tended to refer to the M113 simply as a '113' (spoken as 'one-one-three'), a 'track' or an 'ACAV'. The employ the M113 in many different variants, all designed in Israel, and has given each of them official names, from the baseline 'Bardelas' ( lit. ) to the 'Nagmash' (Hebrew acronym equivalent to 'APC'), 'Nagman', and 'Kasman' variants for urban combat up to the 'Zelda' and 'Zelda 2', which are fitted with -suites. The Australian Army refers to its M113A1s as 'buckets', 'bush taxis' and modified M113A1s fitted with 76 mm turrets as 'beasts'. The German Army has various nicknames, depending on location and branch of service, including 'elephant shoe', 'Tank Wedge' and 'bathtub'.
While some claim that the M113 has been nicknamed the 'Gavin' (after General ), this is not an official designation. One observer said In more than 30 years working in the defense industry, I have never, never heard anybody use the name 'Gavin' for the M-113. Not in the U.S. Nor in any of the many countries that use the vehicle. Not in the military forces, not in the companies that build and equip it, not in the groups that retrofit and repair it. This usage appears not only to be 'unofficial', it is entirely fictional and I believe that you may have been the victim of a hoax or deliberate disinformation.
Australian M113A1 with the T50 turret fitted with twin mounted and machine guns. Armament [ ] The basic M113 armored personnel carrier can be fitted with a number of weapon systems. The most common weapon fit is a single.50 caliber M2 machine gun. However, the mount can also be fitted with a 40 mm automatic grenade launcher. A number of anti-tank weapons could be fitted to the standard variant: the U.S. Army developed kits that allowed the and anti-tank missile systems to be mounted. In the case of the M47, the system mated to the existing machine gun mount, without having to remove the machine gun.
This allowed the commander to use both weapons. A large array of turrets and fixed mounts are available to mount high explosive cannon ranging from 20 mm to 105 mm on to the M113 series, making them function as assault guns and fire support; while in many cases still having room inside to carry dismounted infantry or cavalry scouts. Armor [ ] The M113 is built of, which gives it some of the same strength as steel at a slightly reduced weight, as the greater thickness allows structural stiffness.
The M113A3 was designed to provide protection against 7.62mm threat, and this proved not to be enough when tested in combat. In comparison, modern APCs like the Stryker have an all-around 7.62mm armor-piercing protection, plus 14.5 mm protection on the front, sides, and rear. Also protection against antipersonnel mines through the vehicle floor is installed. Mobility [ ]. Brazilian M113 during an amphibious simulation Its weight allows the use of a relatively small engine to power the vehicle, a Detroit 6V53 of 318 cubic inches (5,210 cc) with an TX-100-1 three-speed. This allows the vehicle to carry a large payload cross-country and to be transported by fixed- and rotary-wing aircraft. Original production M113s can swim without deploying flotation curtains, using only a front-mounted trim vane; they are propelled in the water by their tracks.
Service history [ ] Vietnam [ ]. The 4.2' Mortar Platoon of D/16 Armor, 173rd Airborne on a fire mission in Operation Waco in Vietnam The Vietnam War was the first combat opportunity for 'mechanized' infantry, a technically new type of infantry with its roots in the armored infantry of, now using the M113 armored personnel carrier. In addition, squadrons in Vietnam consisted largely of M113s, after replacing the intended in a variety of roles, and armor battalions contained M113s within their headquarters companies, such as the maintenance section, medical section, vehicle recovery section, mortar section, and the scout (reconnaissance) section. United States Army units in Vietnam were fully equipped with the M113 APC/ACAV, which consisted of one headquarters company and three line companies, normally with an authorized strength of approximately 900 men.
Mechanized infantry battalions and one mechanized brigade were deployed to Vietnam from 1965 until their departure in 1972. Company D, 16th Armor, was the first U.S. Army armor unit deployed to Vietnam. It originally consisted of three platoons of M113s and a platoon of self-propelled anti-tank systems (SPATS). It was the only independent armor company in the history of the U.S. Upon the company's arrival in Vietnam, a fourth line platoon was added; this was equipped with M106 4.2 in.
Mortar carriers (modified M113s). The mortar platoon often operated with Brigade infantry units to provide indirect fire support. It also deployed at times as a dismounted infantry unit.
The remaining SPATS platoon was reequipped with M113s in late 1966 and the mortar platoon was deactivated in early 1967. From early 1967, D/16th had three line platoons equipped with M113s and eventually, its diesel version, the M113A1. It also standardized in late 1968 with three machine guns per track, one M2.50 caliber and two M60 machine guns mounted on each side. Download Film National Treasure 3 Indowebster there. After several years, the machine gun array varied considerably from APC to APC. The company conducted search and destroy missions, road and firebase security. Twenty-five D/16th paratroopers were killed in action and many more were wounded during the course of the war.
Sixteenth Division's largest battle took place on 4 March 1968 at North Tuy Hoa. 'During the day, the company lost 5 men killed, 16 wounded, and 3 missing (who are believed dead as two unrecogizable (sic) bodies were found). The enemy took a much greater loss.
An estimated 2 enemy battalions, 85th Main Force (VC) and the 95th NVA Regiment, were rendered ineffective as they had 297 KIAs, with d-16 Armor receiving credit for killing 218.' The revised official count for D/16 was 8 KIA and 21 WIA. The company commander, Captain Robert Helmick, was awarded the DSC, and many D/16th soldiers earned awards for valor. Sixteenth Division was awarded a Meritorious Unit Award for its actions in Vietnam. It was deactivated in 1969 and the company’s M113s were distributed to E Company, 17th Cavalry, 173rd Airborne Brigade. ACAVs of the 3rd Squadron 11th Armored Cavalry assume a herringbone formation during.
This formation gave vehicles optimal all-round firepower in the event of an ambush in a restricted area. The M113s were instrumental in conducting (RIFs), missions, and large invasions (incursions) such as the on 1 May 1970 and later Laos () in 1971; all of which used the M113 as the primary work horse for moving the ground armies. While operating with and armor units, the M113s often worked in conjunction with U.S. During the Vietnam War, U.S.
Army, along with armored cars, conducted convoy escorts for military traffic. The USAF used M113 and M113A1 ACAV vehicles in USAF security police squadrons, which provided air base ground defense support in Vietnam. Also, M113s were supplied to the ARVN. One notable ARVN unit equipped with the M113 APC, the, earned the. Additional M113s were supplied to the Cambodian, equipped with a turret for the machine gun and a recoilless rifle mounted on the roof. The also used the M113 in Vietnam. After initial experiences showed that the crew commander was too vulnerable to fire, the Australians tried a number of different gun shields and turrets, eventually standardizing with the Cadillac-Cage T-50 turret fitted with two.30 cal Browning machine guns, or a single.30-single.50 combination.
Other turrets were tried as were various gun shields, the main design of which was similar to the gun shield used on the U.S. M113 ACAV version. In addition, the Australians operated an M113 variant fitted with a armored car turret, with a 76 mm gun as a fire support vehicle, or FSV, for infantry fire support. This has now also been removed from service. Subsequent to Vietnam all Australian M113 troop carriers were fitted with the T50 turret.
The FSV was eventually phased out and replaced with a modernized version known as an 'MRV' (medium reconnaissance vehicle). The MRV featured a turret with 76 mm gun, improved fire control, and passive night vision equipment. Recent history [ ].
APC by David E. Graves,, CAT IX, 1969-70. Courtesy of the National Museum of the U.S. M113 Original version, powered by 209 hp (156 kW) V8 gasoline engine. M113A1 Starting in 1964, the gasoline engine was replaced with a 215 hp (160 kW) 6V-53 Detroit Diesel engine, to take advantage of the better fuel economy and the reduced fire hazard of the diesel engine.
The suffix A1 was used on all variants to denote a diesel engine, i.e. An M106A1 was an M106 mortar carrier equipped with a diesel engine. M113A2 In 1979, further upgrades were introduced. Engine cooling was improved by switching the locations of the fan and radiator. Higher-strength torsion bars increased ground clearance, and shock absorbers reduced the effects of ground strikes.
Armored fuel tanks were added externally on both sides of the rear ramp, freeing up 0.45 cubic metres (16 cu ft) of internal space. The weight of the M113A2 was increased to 11,740 kilograms (25,880 lb). Because the added weight affected its when afloat, it was no longer required to be amphibious. Four-tube smoke grenade launchers were also added. The suffix A2 is used on all variants to denote upgrade to A2 standard.
M113A3 In 1987, further improvements for 'enhanced (battlefield) survival' were introduced. This included a yoke for steering instead of laterals, a more powerful engine (a 6V-53T Detroit Diesel), external fuel tanks and internal spall liners for improved protection. The suffix A3 is used on all variants to denote upgrade to A3 standard.
M113 armored cavalry assault vehicle (ACAV) variant. M113 ACAV in Vietnam, 1966 The 'armored cavalry assault vehicle' or 'ACAV', was a concept and field modification pioneered by the ARVN in 1963 during the Vietnam War. The ARVN troops utilized the M113 armored personnel carrier as an infantry fighting vehicle, and more often than not, as a light tank by fighting mounted rather than as a 'battle taxi' as dictated by U.S. After it was found that the commander and positions were extremely exposed, and hence the commander and troops were vulnerable to enemy fire, South Vietnamese engineers thought out a simple and cheap remedy to this problem: Initially, field expedient shields and mounts were made from sunken ships, but this was soft metal and could be penetrated by small arms fire. Then armor plate from scrapped armored vehicles was used; this worked well, and by the end of 1964 all ARVN ACAVs were equipped with gun shields.
Army, ACAV sets were produced industrially in Okinawa for the 12.7 millimetres (0.50 in) machine gun, and rear aft and starboard M60 machine gun positions. Finally, the ARVN's ACAV modifications were adopted by the U.S. Army in Vietnam, and by 1965 the full ACAV set was mass-produced in the U.S. The kit included shields and circular turret armor for the commander's M2 12.7 mm machine gun, and two additional 7.62 mm M60 machine guns, again with shields, fitted on either side of the top cargo hatch. This kit could be retrofitted to any M113.
ACAV sets were sometimes fitted to the, but the different rear hatch found on this vehicle required the left M60 machine gun to be fitted to the extreme rear instead of the side. Many kits were added in the field, but at least in the case of the, the vehicles had their ACAV sets installed in the U.S. Prior to their deployment to Vietnam in 1966 from, Maryland. Additional armor in the form of a mine protective kit under the hull was also frequently fitted.
Derivatives [ ]. Soldiers fire the system out of an M113 at Camp Taji, Iraq, 2009.
System A smoke screen generator vehicle A mortar carrier armed with an 106.7mm (4.2 inch, or 'Four-deuce') mounted on a turntable in the rear troop compartment. On this variant, the single hatch over the rear troop compartment was exchanged for a three-part circular hatch. The mortar could be fired from the vehicle, but could also be fired dismounted.
Currently, the U.S. Army mortar carrier is the M106 upgraded to A3 standard and armed with an M121 120mm mortar, a variant of the Armed with an M121 120mm mortar, a variant of the M120 mortar. M125 Another mortar carrier, basically an M106 armed with an 81mm mortar Variant equipped with a turret armed with a and a.50 caliber machine gun. These vehicles are no longer used by the U.S. Vehicles upgraded to A1 standard were known as 'M132A1s'. M150 Anti-tank variant equipped with a TOW ATGM launcher Anti-aircraft variant equipped with a turret armed with a variant of the 20mm cannon Anti-aircraft variant equipped with a launcher armed with four missiles Unarmored cargo carrier equipped with a rear cargo bed.
M113 fitter and repair vehicle M577 Command variant, the roof over the rear troop compartment is higher. The vehicle also carries additional radios and a generator. A variant of this is the M1068 standard integrated command post system carrier, equipped with the newest U.S. Army automated command and control system. M579 A fitter and repair vehicle equipped with a crane.
This vehicle was not taken into U.S. Army service. M806 Repair and recovery vehicle equipped with an internal winch and two earth anchors mounted on the rear hull (improved TOW vehicle) Equipped with a launcher armed with two. M113 'MBT' (NTC) A variant of the M113 fitted with a modified Bradley turret as part of a vismod package specifically for training. This version also features MILES gear, a MGSS/TWGSS system, and fake ERA around the turret.
(command and reconnaissance) A lowered and shortened version of the M113 developed for the Netherlands. It was used for reconnaissance duties with cavalry battalions and armoured engineer companies. It had four road wheels on either side. The engine was moved to the rear of the vehicle although the drive sprockets were maintained at the front. Armament was a 25mm cannon in a remotely operated turret.
Crew consisted of commander, driver and gunner. It has also been used by the Canadian Army as 'Lynx reconnaissance vehicle'. A development of the M113A1 APC, upgraded with an enclosed turret and firing ports. Others A huge number of M113 variants have been created, ranging from infantry carriers to nuclear missile carriers. The M113 has become one of the most prolific armored vehicles of the second half of the 20th century, and continues to serve with armies around the world into the 21st century.
Not without its faults, the otherwise versatile chassis of the M113 has been used to create almost every type of vehicle imaginable. Few vehicles ever created can claim the application to such a wide range of roles.
In 1994, a stretched version of the M113 was presented by its manufacturer, also known as 'mobile tactical vehicle light' (MTVL). Its hull is lengthened by 34 inches and equipped with an additional road wheel (six on each side) to sustain the added dry weight and payload. The vehicle was developed as a 'production-tooled demonstrator' with private-industry funding from United Defense.
Although the U.S. Army did not buy it, it was acquired by other nations, and is copied today by Pakistan, Turkey and Egypt in their local M113-producing plants. Some nations, like Canada and Australia, also stretched existing M113-hulls.
M113 copies Several countries acquired M113s and later copied the design and proceeded to produce clones or evolved models (post-M113A3-standard) in their own indigenous factories. Pakistan produces an armored personnel carrier known as which has a number of mechanical and automotive parts in common with the M113. Turkey produces the based on the.
Egypt produces many variants of the M113A4 including the (EIFV), which features a combination of an M113A3-base and the fully functional and stabilized two-man turret of the M2 Bradley. Iran is also producing its own M113s. Operators [ ]. •,,,,,,,,,, and the 1st Brigade, 5th Infantry Division (Mechanized). Army 1st Brigade, 5th (Mech) Infantry Division in Vietnam was not composed of strictly mechanized infantry battalions. The 5th (M) ID (1st Bde), consisted of: the, (straight leg-no armored vehicles), ( tanks),, A Troop (only one troop of cavalry), and the OPCON (operationally controlled) /attached from the 9th Infantry Division.
The one of the 12th and the full of the 5th Armored Cavalry were and M113 ACAV equipped.
Contents • • • • • • • • • • • AT Commands A - M [ ] This module explains the AT commands A to M as used by a 'generic' Hayes-compatible modem. Different modems use slightly different commands. However, this list is supposed to be as 'generic' as possible, and should not be extended with modem-specific commands.
Instead it is recommended to provide such command lists in an Appendix. A: Answer Command [ ] Syntax: A Description: The command initiates handshake as answering side. No next commands in this command line are proceeded.
If handshake succeeds, modem sends successful message ('CONNECT.' ) to serial line and serial line switches to data mode, otherwise failure message is sent and serial line remains in command mode. Result Codes: Result Codes Code Description CONNECT Handshaking succeeds NO CARRIER Handshake failed CONNECT message usually contains speed, protocol and other details of succeeded connection and may be preceded with other messages of connection details. Related Commands and Registers: • • • • B: Select Communication Standard [ ] Syntax: B[0 1] (original Hayes) B[number] (extensions) Description: In original Hayes modems, it selects protocols for 300bps and 1200bps handshake: B0 selects CCITT protocols; B1 selects Bell protocols. Some vendors (e.g.
Rockwell) extends it to limit connection speed (e.g. B15 - no more than 28800 bps). Result Codes: Result Codes Code Description OK Speed/protocol selection succeeded ERROR Speed/protocol selection failed Related Commands and Registers: • A: Answer • D: Dial • +MS: Speed and protocol selection C: Carrier Control Selection [ ] Syntax: ''ATC0'' The carrier detect (CD) override is always on (default) ''ATC1'' The modem sends the carrier detect signal when it makes connection with another modem and drops the signal when it disconnects.
Description: Controls the carrier detect signal sent by the modem to the computer.. DTE Interface: If AT&C1, the carrier detect enters into a true state when a connection is made. The carrier detect returns to a false state after the connection is dropped. Aborting Events: None Related Commands and Registers: • D: Dial Command [ ] Syntax: D [T P digits misc] Description: The command initiates dialing a number using pulse or tone dialing. The dial string can be rather flexible. Almost all of the modem's default settings can be overridden in the dial string. Dialing is controlled by providing dial modifiers after the D command.
Dial Modifiers: 0-9 Digits. This results in the corresponding DTMF tone being sent (tone dialing), or the corresponding number of pulses (pulse dialing) being sent. A-D, #, * (Tone dialing only) Tone dialing supports six more characters, which can be dialed in addition to the numbers 0-9. However, these characters can trigger special functions in the telephone network and should only be used if their function is required in a particular network.
NOTE, one of the nastiest things which can be triggered in some public networks with these characters is a test of the tariff time switch. The test consists of a rapid increase of the counter, which can end up at the phone bill as a huge debt. P Pulse Dialing Modifier. Indicates that all following numbers should be dialed using puls dialing, until a T modifier is encountered. The modifier is persistent.
It not only affects the current dialing, but also any other dialing (until a T modifier is encountered or the modem is reset). T Tone Dialing Modifier. Indicates that all following numbers should be dialed using DTMF dialing, until a P modifier is encountered. The modifier is persistent.
It not only affects the current dialing, but also any other dialing (until a P modifier is encountered or the modem is reset). W Wait for Second Dial Tone. This is useful when working behind a PABX. Typically to dial out from behind a PABX it is first necessary to seize an external line by dialing a special number, and then waiting for the public line's dial tone before continuing., Delay. The modem will pause for the delay configured in register S8 before continuing dialing. This is useful when dealing with old, slow mechanical telephone equipment, as well as working in special PABX configurations. Some PABX need some time to seize a line, but provide no progress indication when they have done so.
Note, if a second dial tone is provided, then the W modifier is a much better choice over the, modifier. @ Wait for Silence. This is another modifier which is helpful in dealing with special PABX configurations. The modem waits for at least five seconds of silence before continuing dialing. Silence is defined as no signal in the call progress indication frequency band, not as absolute silence (not as absence of line noise). If the modem doesn't detect these five seconds of silence prior to the expiration of the S7 call abort timer, the modem stops the dialing (call abortion), and returns a NO ANSWER result code. This is somewhat counter intuitive, since the modem is waiting for silence as an answer.
If busy detection is enabled, some modems return a BUSY answer code instead. Which is also arguable. If an answer tone from some remote modem arrives while waiting for the five seconds of silence, the modem initiates the handshake procedure and aborts dialing.
If the handshake succeeds the modem is on-line.! A flash is a special signal send to some telephone equipment, like a phone exchange. The flash is send by (ab)using the hock. The modem goes on-hock for a specific time. That time is exchange-equipment / telecom-standard specific. It has to be shorter than the on-hock time which is interpreted by the exchange as call/dialing abortion.
The flash time can be configured via the modem's S29 register. Some PABX require a flash if they are supposed to seize a public line.; Return to Command State after Dialing. This modifier indicates the end of the dialing, but instead of requesting the modem to go into the call progress state, the modem will return to the command line. This enables to send additional AT commands to the modem while the modem is still off-hock.
These additional commands may be placed after the; on the same command line, or can also be send on additional command lines. To continue the call, an additional dial command, e.g. A single ATD needs to be sent, which will transition the modem's state to enter call progress. Alternatively, the call can be aborted by sending the on-hock command ATH0. S=n Dial Stored Telephone Number. Dial one of four (n = 0.
3) telephone dial strings. See the &Z command for how to store a number in the modem. R Originate Call in Answer Mode.
Originate the call, but behave as being called instead. The modem expects that handshake negotiation is reversed. This is often not implemented in today's modems, and the modifier is ignored. Modern modems accept and support a number of additional modifiers. E: Command State Character Echo Selection [ ] Syntax: E[0 1] Description: Switches character echo on (1) or off (0) when in the command state.
Given no argument, assumes 0. Character echoing is usually not desired when controlling a modem via some software program. It is useful for debugging purposes, and when the modem is controlled manually, e.g. Via some generic terminal program. Result Codes: Result Codes Code Description OK Parameter was valid ERROR Bad number specified; must be either 0 or 1.
F: On-line State Character Echo Selection [ ]. This page or section is an undeveloped draft or outline. You can help to, or you can ask for assistance in the. Command Description Template Syntax: Description: Result Codes: Result Codes Code Description OK Parameter was valid ERROR Otherwise Related Commands and Registers: • H: Hook Command Options [ ] Syntax: H[0 1] Description: Controls if the modem goes on-hook (disconnects from the phone line), or off-hook (connects to the phone line). The wording is taken from normal telephone usage, where someone takes the handset off the hook (off-hook) when intending to place a call. The terminology is counter-intuitive for modems, since off-hook indicates the modem goes on-line, and on-hook indicates the modem goes off-line.
H or H0 The modem will release the phone line (going on-hook) if the modem is currently on-line (off-hook). The command is also typically used to terminate a modem's self-test or automatic line test mode - if provided by a particular modem. The modem will go into command mode after the command. In order to issue the command while on-line, and while not in command mode, the escape code sequence need to be sent prior to the command, to force the modem in command mode first. H1 If on-hook (off-line), the modem will go off-hook (on-line), and remain in command mode.
Typically, the next command in command mode is a D dial command. If the inactivity timer S7 expires while off-hook, the modem goes back on-hook (off-line).
This behavior prevents accidental blocking of a phone line by broken DTE software which manages to go off-hook but for whatever reason doesn't use the seized line. Result Codes: Result Codes Code Description OK Parameter was valid. ERROR Otherwise. Related Commands and Registers: • A: Answer • D: Dial I: Internal Memory Tests [ ]. This page or section is an undeveloped draft or outline.
You can help to, or you can ask for assistance in the. Command Description Template Syntax: Description: Result Codes: Result Codes Code Description OK Parameter was valid ERROR Otherwise Related Commands and Registers: • L: Speaker Volume Level Selection [ ]. This page or section is an undeveloped draft or outline. You can help to, or you can ask for assistance in the. Command Description Template Syntax: Description: Result Codes: Result Codes Code Description OK Parameter was valid ERROR Otherwise Related Commands and Registers: • M: Speaker On/Off Selection [ ] Syntax: M[0 1 2 3] Description: 0 switches the internal speaker always off. 1 switches the internal speaker off when connected and on otherwise.
2 switches the internal speaker always on. 3 switches the internal speaker on when not connected or during retrains, and off during normal connection. Some vendors add additional modes. Result Codes: Result Codes Code Description OK Speaker mode setting succeeded.
ERROR Speaker mode setting failed. Related Commands and Registers: • L: Set internal speaker loudness.