LLM1100 Bell 202/CCITT V.23 1200 Baud Modem


  • Long-range data communication via frequency shift key (FSK) simplex, half and full-duplex modem
  • Ideal for non-switched private wire (spare pair) or leased telephone lines or any dedicated wire pair*
  • Two or four wire operation
  • Seamless interface with most PLCs, RTUs and PCs
  • Easily field configured or factory pre-configured for your application
  • Transmits up to 20 miles (32 km) on unloaded lines or unlimited transmission on loaded lines *

The Data-Linc Group LLM1100 is a Bell 202 (CCITT V.23 optional) 1200 baud modem. It can be easily configured for simplex (bit mode), half-duplex and full duplex operation. The LLM1100 is designed to be used on private, leased non-switched telephone lines or any dedicated two-conductor wire (twisted or untwisted, shielded or unshielded).

The LLM1100 is microprocessor-based— when the carrier shuts off, data bit errors are eliminated. This reduces retransmissions for trouble-free PLC communications. The LLM1100 also incorporates a unique data sense carrier control feature that eliminates the need for RTS/CTS control on multi-point Remotes.

The LLM1100 easily interfaces with most PLCs, RTUs and PCs. The LLM1100 supports RS232 interface.

The LLM1100 has a range of 20 miles (32 km) on any ordinary wire pair or unlimited on loaded telephone company voice grade (VG-6) leased lines or equivalent.*

*dependent upon wire size and line quality

Download (628K) the pdf version of the Data Sheet for the LLM1100 Bell 202 Modem. (Requires Adobe Acrobat Reader to open.)

Industrial Applications

The LLM1100 is ideal for systems that require:

  • Extended communications over private or leased telephone lines
  • Compatibility with Bell 202 or CCITT V.23 modems

LLM1100 Specifications

Up to 20 miles (32 km) on unloaded lines or
unlimited range on loaded lines1

Serial Data Interface
RS232, 10 or 11 bit asynchronous
Throughput. 300, 600, 1200 Baud
Flow Control. RTS control or DSCC (Data Sense Carrier Control)
Serial Connector. DB9 female

Carrier Interface
Protocol. Bell 202, CCITT V.23 (Bell 202 default)
Carrier Connector. Removable Terminal Block

Operation Modes2
Point-to-point, point-to-multipoint
Two wire/four wire
Simplex, half-duplex and full-duplex (Full-duplex
requires four wire and point-to-point mode.)

Supply Voltage. 11 – 24 VDC; 12 VDC wall mount
transformer supplied with modem.
. 60mA @ 12 VDC
Power Connector. Center Positive Barrel Jack or
Removable Terminal Block

Operating Environment
. 32° to 140°F (0° to +60°C)
Humidity. 0 to 95% non-condensing humidity

Standard. NEMA 1; 18-gauge steel;
1.54″ x 4.90″ x 7.75″ (3.9 x 12.4 x 19.7 cm) including mounting flanges

2 lbs (0.91k)

LLM1100 Bell 202/CCITT V.23 1200 Baud Enclosure Dimensions 

1 Loaded lines require TELCO VG-6 spec lines or equivalent. Line conditions, size and noise will effect overall performance. Shielded wires should not be used. Line loss between any two devices in the network cannot be more than 17dB.

2 To help with the proper application of the modems, please provide your Data-Linc Group sales representative with a detailed diagram of the proposed application.

Specifications subject to change without notice.

P/N 155-09987-004