ProSoft MVI56-GEC Ethernet Communications Interface Module

The ProSoft MVI56-GSC, also cataloged as the MVI56-GEC Generic ASCII Ethernet Communications Interface Module, serves as the primary MVI56 interface module utilized to execute bidirectional raw ASCII data transfers over Ethernet networks across Allen-Bradley ControlLogix platforms.

Hardware Specifications

Backplane Bus Communication Velocity & Data Architecture

The module interfaces with the ControlLogix processor across the 1756 backplane using scheduled block transfers governed by the controller's asynchronous ladder logic runtime. By isolating raw ASCII TCP/IP encapsulation tasks onto an independent onboard communication processor, the unit preserves the master PLC CPU processing bandwidth.

The 500 V optical isolation protection layer guards internal backplane logic components from field-side electrical transients encountered on the 10/100 Base-T network infrastructure. Serial character streams are buffered locally, preventing data overflow and packet degradation under peak network data rates.

Frequently Asked Questions

Q: Does the MVI56-GEC module support Remove and Insert Under Power (RIUP) operations? A: Yes. The module electrical interface satisfies standard 1756 chassis bus specifications, allowing hot-swap module replacement while the backplane is energized. Extraction will immediately terminate active Ethernet sockets and halt asynchronous logic data transfers.

Q: Can the RS-232 configuration port (CFG) be used for runtime ASCII communication? A: No. The dedicated RJ45 RS-232 serial port is strictly limited to terminal diagnostics, system configuration setup, and firmware flashing via the ProSoft Configuration Builder software utility.

Q: What is the impact on data packet integrity if the ladder logic scan time is slower than the incoming network data velocity? A: The module contains internal FIFO ring buffers to store incoming ASCII character streams. If the backplane block transfer rate fails to pull data rapidly enough, the local buffer prevents character drops until its capacity is exceeded, at which point an overrun error bit is set in the module status block.

Field Installation Guidelines

• Chassis Alignment and Ingress Protection: Power down the ControlLogix system prior to insertion if required by plant safety standards. Insert the single-slot module into the 1756 chassis along the designated alignment guides until the upper and lower locking tabs click securely to the rail.
• Network Infrastructure Shielding: Connect the 10/100 Base-T interface using high-quality Category 5e or superior shielded twisted-pair (STP) copper cabling. Ground the cable shield solely at the network switch enclosure to prevent common-mode ground currents from looping through the module chassis.
• Serial Diagnostic Connection: For initial configuration via the CFG port, utilize an RJ45 to DB9 adapter cable wired for standard null-modem serial execution, matching the communication velocity constraints of the host engineering station.