Dial-Up/Leased Line



DLM4500 Industrial Dial-up/Leased Line Extended Temperature Modem


  • Ideal for industrial dial-up, leased line, private line or dedicated wire applications
  • Extended temperature range -40°C to +80°C (-40°F to +176°F)
  • Optional auto-dial module for alarm conditions or emergency calls just by sensing a logic flag from the remote PLC
  • Versatile, reliable and durable— designed especially for industrial applications
  • Easily interfaces with most PLCs, RTUs and PCs
  • Factory or field configured for your application— ensuring trouble-free installation
  • Supports most serial protocols, including DF1, GE-SNP, Modbus ASCII, DNP, and Optomux. (For Modbus RTU, please contact Data-Linc)

Contact Data-Linc Group for an application review.

DLM4500 voice band modem offers maximum versatility and reliability in remote process control and data acquisition. From Dial-up, leased and private line applications, the DLM4500provides unsurpassed flexibility in any industrial application requiring extended temperatures.

The DLM4500 uses advanced Trellis coding, error correction and data compression technology for virtually error-free data communications. An uncompressed PLC line speed of up to 19.2 Kbaud is standard; however, port baud rates of 1200through 115.2 K are also available.

The DLM4500 operates full/half-duplex on two wires. The asynchronous digital interface can be either RS232/422 or AE485*. The DLM4500 autoanswerAE485* version easily provides long distance polling of multiple PLCs at a remote site. The polling operation performed by the Master is completely transparent to the DLM4500. No additional Master programming is required— simply enter the Remote DLM4500 telephone number.

Housed in a rugged steel enclosure for optimal EMI resistance, the DLM4500 series is factory configured for trouble-free installation. No programming or configuration is required.

Auto Alarm Dial Back

An Auto Alarm Dial Back module is available on theDLM4500. This gives the remote PLC the ability to establish a data path to a master PLC or PC via a logic input from the remote PLC to the Auto Alarm Dial Back module. This could be used for remote alarming or time based data updates.

Industrial Applications

  • SCADA system communications
  • Remote PLC programming and diagnostics
  • Remote alarm monitoring
  • PLC/RTU communications

* AE422/485 Auto Enable function compatible with RS422/485

Download (file size 552K) a printable pdf version of the Data Sheet for the DLM4500 Dial-up/Leased line extended temperature modem. (Requires Adobe Acrobat Reader to open.)

See also Technical Services > Engineering Specifications > DLM4500-Dial-up

DLM4500 Series Specifications

EMI/RFI. FCC Part 15, Class B, DOC Class/MDC Class B
Phone Compatibility. FCC Part 68

Ringer Equivalence 0.30B

Carrier Trellis Coded Modulation (TCM) 1700 or 1800 Hz

Modem Communication. ITU-TSS (CCITT) V.34, V.43 bis,
V.32, V.23, V.22 bis, V.22 and V.21;
Bell 212A and 103/113
Error Correction. V.42 (LAP-M or MNP 3-4)
Data Compression. V.42 bis (4:1 throughput) MNP Level 5 (2:1 throughput)

Telephone Line. Modular TELCO, RJ-11
Serial Port. DB9 female
Power. 2 Position Pluggable Terminal Block

Flow Control
User selectable options; function disabled at factory

Two-wire dial-up or two-wire leased lines

Modem Data Rate
Up to 33.6 Kbps with data compression, 19.2 Kbps
maximum factory speed, 9600, 4800 and 1200 bps

DTE Speeds Supported
Up to 115.2 Kbaud

Dial Type

Transmission Level
-11 dBm

Receiver Sensitivity
-43 dBm

20 miles* (32 km) on unloaded line, unlimited for
loaded lines and dial-up applications

Internal Memory
RAM. 60 character command buffer
NVRAM. One stored factory profile

User Controls
Standard. AT Command Set
Optional. Auto Answer/Dial Back internal discrete signal control module

Tests using &Tn

Data Connections
Standard. DB9 female DCE
Optional. Two wire AE485 or four wire AE422
(AE485 and AE422 Auto Enable are RS485/422 compatible in most cases)

Data Format
Serial, binary, asynchronous 10 or 11 bit

Standard. Wall mount power supply, 110/120 VAC to 9 to 18 VDC, 800 mA
Optional. 24 VDC (user supplied) power interface, two position terminal block. 24 VDC, 300 mA

Operating Environment
Temperature. -40° to 176°F (-40° to +80°C)
Humidity. 0 to 95%, non-condensing

Standard. NEMA 1; 18-gauge steel with mounting flanges.
Dimensions. 9.00 in D x 4.90 in W x 1.54 in H
(22.86 cm x 12.45 cm x 3.94 cm)

1.68 lb. (0.76 kg)

Industrial Stand-alone Enclosure

Wireless Ethernet Modem Dimensions Diagram
* Depends upon line quality

Specifications subject to change without notice.
All trademarks are the property of their respective owners.
P/N 155-08990-005