Description
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 3150-MCM |
| Manufacturer | ProSoft Technology |
| Product Type | Modbus Master/Slave Communication Module (Interface Module) |
| Platform | Allen-Bradley SLC 500 / 1746 I/O chassis (SLC 5/02, 5/03, 5/04, 5/05) |
| Form Factor | Single-slot 1746 module, 1747-KE compatible footprint |
| Serial Ports | Two independent ports, DB-9 male connectors, RS-232 / RS-422 / RS-485 (2-wire and 4-wire), jumper selectable |
| Protocol Support | Modbus RTU Master, Modbus RTU Slave, Modbus ASCII Master (7- or 8-bit), Modbus ASCII Slave (7- or 8-bit) |
| Modbus Function Codes | 01, 02, 03, 04, 05, 06, 15, 16 |
| Baud Rates | 300, 600, 1200, 2400, 4800, 9600, 19200, 38400 bps (both ports share the same upper limit) |
| Data Bits / Parity / Stop Bits | 7 or 8 data bits; none, odd or even parity; 1 or 2 stop bits |
| Slave Address Range | 1 to 247 |
| Command List Capacity | Up to 100 command entries per module |
| Data Transfer Capacity | Up to 4000 registers mapped to SLC/PLC data tables |
| Data Types Supported | ASCII, binary, floating point; configurable data table mapping |
| Optical Isolation | 500 V from backplane |
| Backplane Current Load | 0.15 A at 5 V DC; 0.04 A at 24 V DC |
| LED Indication | Module status, backplane transfer, serial TX/RX, serial error |
| Configuration Method | Configuration data held in SLC data table; ProSoft Configuration Builder software |
| Processor Interface | Emulates 1746-BAS-5/02 BASIC module with M0/M1 file capability in RSLogix 500 |
| Termination | Screw termination provided for RS-422/485 (two per module) |
| Handshaking | RTS/CTS and DTR supported on RS-232 |
| Operating Temperature | 0 °C to +60 °C (32 °F to 140 °F) |
| Storage Temperature | -40 °C to +85 °C |
| Relative Humidity | 5% to 95%, non-condensing |
| Dimensions (H × W × D) | Approximately 5.1 cm × 12.7 cm × 15.2 cm (2.0 × 5.0 × 6.0 in) |
| Weight | Approximately 0.4 kg |
| Certifications | CE, UL, CSA |
| Installation Note | Not hot-swappable; chassis power must be removed before insertion or removal |
Main Features and Advantages
In-chassis Modbus integration without external gateways: The strongest argument for the 3150-MCM is architectural simplicity. Because it lives in the 1746 rack and talks to the processor over the backplane through M0 and M1 files, it removes the protocol converter, its enclosure, its power supply and its associated wiring from the design. Data written to M1 files by the ladder program is transmitted on the next block-transfer cycle, and data received from the Modbus network appears in M0 files that the SLC scan reads as ordinary inputs. For an engineer integrating a Modicon PLC, a Yokogawa or Honeywell DCS node, or a rack of Modbus drives into an SLC-based machine, the 3150-MCM turns a multi-vendor integration project into a configuration exercise.
Dual independently configurable ports: Unlike single-port solutions, the 3150-MCM offers two serial ports, each of which can be assigned as a Modbus master or slave, in RTU or ASCII mode, at its own baud rate, parity and stop-bit setting. This allows genuinely useful topologies: one port polling a multidrop RS-485 network of field devices while the second presents the SLC as a Modbus slave to a supervisory DCS or SCADA master. Pass-through mode and slave-to-master routing are also supported, so devices on one port can be reached through the other, extending the reach of the Modbus network without additional hardware.
Industrial-grade electrical design: Both serial ports on the 3150-MCM are optically isolated to 500 V from the backplane, which is what allows the module to survive in installations where field devices are grounded at different potentials or where long RS-485 runs pick up common-mode voltage. Jumper-selectable RS-232, RS-422 and RS-485 operation on each port means one part number covers point-to-point and multidrop applications, and screw terminations for RS-422/485 network ends are supplied with the module. Support for satellite and packet radio, with programmable inter-character timeout on each port, makes the 3150-MCM a proven choice for remote telemetry over radio and leased-line modems.
Commissioning and diagnostics: Configuration for the 3150-MCM is stored in the SLC data table and authored with ProSoft Configuration Builder, with a documented sample ladder project that gets a first-time user communicating in a single session. Front-panel LEDs distinguish module status, backplane transfer and per-port transmit, receive and error activity, so a technician can determine whether a fault lies in the configuration, the backplane or the serial link without a protocol analyser. Diagnostic registers expose per-port master and slave status, and configurable message response timeout, retry count and inter-message delay let the module be tuned to slow or noisy networks rather than forcing the network to meet the module.
