Redundant fiber PLC-5 in-chassis Ethernet networking modules for PLCs and Ethernet field devices

Multi-fault tolerant, Ethernet communications built for industrial PLC-5 applications

The OCM fiber Ethernet networking module is not an IT switch.  The PLC-5 in-chassis OCM module is an OT (operational technology) networking module that is built for critical industrial Ethernet applications and networking together Ethernet PLCs.

Industrial applications for Ethernet networking are different from IT applications.  If a networking module fails, it needs to be hot swappable and plug and play, not complicated with command line interface programming; and taking minutes for boot up is not acceptable on the plant floor after power cycle.

An industrial Ethernet module needs to be able to transport multiple industrial Ethernet protocols, at the same time -- for example Ethernet/IP, PROFINET, and Modbus TCP, and have options for other industrial protocols such as ControlNet, Data Highway, IEC 61850, R/IO, GE Genius, RS-232, RS-485, RS-422, CTI, Siemens, Texas Instruments Remote I/O, and Modbus Serial.

And, it needs to be compatible with any vendors PLCs or DCS.

That's exactly what the Phoenix Digital fiber Ethernet networking modules provide, and they are available as DIN rail mount, ControlLogix in-chassis modules and PLC-5 in-chassis modules.

The OCM module is a PLC-5 in-chassis Ethernet module that is engineered specifically for the 1771 PLC-5 platform, Siemens / CTI / IT platform, and GE Genius 90-30 I/O.

The OCM module supports Modbus, Data Highway, Remote I/O, ControlNet, CIT / Siemens / Texas Instruments Remote I/O, RS-232, RS-485, RS-422, and GE Genius.


Built-for control engineers

  • Allen Bradley PLC-5 in-chassis PLC module
  • No command line interface configuration
  • Plug and play, hot swapable
  • 10-second power-up
  • Transports multiple industrial protocols at the same time

Built-for critical networks

  • Redundant fiber between OCR modules
  • Fiber facilitates long distances, eliminates ground loop issues, and impervious to EMI
  • Copper Ethernet to PLCs and field devices
  • 0 second network convergence time if a fiber fails or a module fails

Technical Data

Technical Data
Specifications Fiber Optic Type
Mating Connector
Transmit Launch Power
Receive Sensitivity
Single Mode or Multimode
-15 dBm (Typical Multimode; -18 dBm (Single Mode)
-32 dBm
Power Supply Plug-In Modules (Typical)
Standalone Modules (VAC)
Standalone Modules (VDC)
+5 VDC, 1.5 to 1.8 Amps
120/220 VAC, 8-10 Watts
24 VDC, 8-10 Watts
Environmental Operating Temperature
Storage Temperature
Relative Humidity
0° to 60° C (32° to 140° F)
-40° to 85° C (-40° to 185° F)
0 to 95% RH, noncondensing
Dimensions OCM Module
Panelmount, Standalone
Single Slot 1771 Chassis, Single Slot GE 90-30, Single Slot CTI Series 2500
10.38” H x 3.50” W x 6.14” D
(154.9mm H x 78.7mm W x 139.7 mm D)

Order Information

Part Numbers  
OCM-CTN-(1)-(2)-(3)-(4)-(5)-(6)-(7) ControlNet Communications
(1771 Plug-In and Panelmount, Standalone modules)
(1) “85”
850 nanometer wavelength selection
1300 nanometer wavelength selection
1550 nanometer wavelength selection
(2) “P”
Panelmount, Standalone Enclosure  (OCM modules only)
DIN Rail, Standalone Enclosure (OCX modules only)
1771, 1746, or 1756 Plug-In Module
(3) “D”
Interactive Diagnostics (Required for OCX CL I, DIV 2)
No Diagnostics
(4) “ST”
ST Fiber Optic Connector Style
SMA Fiber Optic Connector Style (Available with 850nm wavelength only.)
(5) “24V”
24 VDC Operation
120/220 VAC, 50/60 Hz Operation
125 VDC Operation
(6) “SM”
Singlemode Fiber Compatibility (Available with 1300 nm or 1550 nm Wavelengths, and ST connector options only.)
Multimode Fiber Compatibility
(7) “EXT” = Extended Capacity Operation (Required for networks with 28 or more OCM/OLC/OCX-CTN modules.)


Phoenix Digital network communications architecture

This video explains typical applications, types of devices connected, how the redundant fiber ring backbone is connected to each module, and what happens when a fiber or module breaks and what you have to do to repair the link.

Phoenix Digital networking diagnostic software

How to use the Phoenix Digital networking diagnostic software to troubleshoot modules or your network.


Softing Inc.