ProSoft MVI56-GSC Generic ASCII Serial Communication Module

The ProSoft MVI56-GSC, also cataloged as the MVI56GSC Generic ASCII Serial Communication Module, operates as a dedicated hardware component for ASCII serial character processing within Allen-Bradley ControlLogix backplane platforms.

Hardware Specifications

Protocol Conversion Latencies & Serial Execution

The module serves as a bidirectional raw character pipeline between the control processor and peripheral serial hardware. Data packets are read from and written to the module memory registers via asynchronous backplane block transfers managed through the host controller ladder logic.

Internal microprocessing paths optimize protocol conversion latencies by buffering incoming character streams independently per port prior to backplane encapsulation. This hardware-level separation limits internal loop transit delays, preventing byte stream serialization bottlenecks during high-frequency barcode transmissions or weighing matrix processing cycles.

Frequently Asked Questions

Q: Does the MVI56-GSC support Remove and Insert Under Power (RIUP) actions? A: Yes. The module's mechanical interface complies with standard 1756 ControlLogix backplane design, allowing hot-swapping while the chassis is live. However, live extraction immediately terminates raw serial buffer processing and results in lost data characters on active asynchronous links.

Q: Can the two onboard serial channels be configured for different physical layer standards simultaneously? A: Yes. Port 1 and Port 2 are completely independent electrical circuits. Hardware jumpers on the module motherboard permit one channel to be configured for RS-232 point-to-point signaling while the alternate channel executes on an RS-485 or RS-422 multi-drop network.

Q: How is the raw character buffer managed when a packet exceeds the backplane block size allocation? A: The module firmware parses data using defined termination characters or packet byte timeouts. When an incoming data stream exceeds a single backplane transfer block, the module partitions the characters across consecutive data blocks, utilizing internal pointers to maintain original payload order for the PLC logic.

Field Installation Guidelines

• Chassis Alignment Constraints: Ensure the 1756 ControlLogix chassis is adequately bonded to earth ground. Align the module card edges with the designated slot guides and press firmly until both the top and bottom extraction tabs snap lock onto the chassis rim.
• Serial Signal Grounding and Shielding: Install raw serial runs utilizing high-quality shielded cables. Terminate the drain wire exclusively at the enclosure grounding bus bar to prevent high-frequency common-mode noise propagation from distorting the differential RS-485/422 data streams.
• Termination of Multidrop Cables: When deploying the module over an RS-485 or RS-422 bus layout, confirm that appropriate 120-ohm end-of-line resistors are fixed across the rx/tx terminal pins of the most distant physical nodes to avoid wave reflections.