MRBus MRB-PCIM Panel Control/Indicator Module

MRBus MRB-PCIM Panel Control/Indicator Module

Panel CTC Control/Indicator Module

The Panel CTC Control/Indicator Module serves as the front end for up to 8 CTC control points (basically four sidings, since each end counts as a control point). It provides inputs for East/West Clearance switches, Normal/Diverging turnout position switches (if needed), code buttons, and LED drivers for occupancy, turnout position, and clearance.

Construction notes: The switches are all common-ground. The turnout switch is SPST, and is connected between the turnout input and ground. The clearance direction switch should be SPDT-Center Off (rotary switches would be prototypical, but I usually use toggles), with the center hooked to ground and the two poles hooked to the correct east and west switch inputs. The code button is obviously a momentary SPST switch from the code input to ground. Also, the LEDs are all matrixed. Please refer to the LED Matrix document to determine where and how LEDs should be wired.

At the moment, the module is designed to only control 4 MRB-CSCN units. In the future, as I build more generic nodes, I'll expand the PCIM to control them as well.

As has been mentioned elsewhere, the MRBus system has been developed in C using Pavel Baranov's C2C compiler. It's not free, but it's quite reliable and very reasonably priced for what it does and there is a free trial version available. For those looking for a good quality PIC C compiler on an affordable budget, I recommend it. As a truly free, open-source PIC compiler becomes available and matures (come on, SDCC people, I'm counting on you...), I'll probably migrate over. For those without the compiler, I've included the compiled hex file for use with pretty much any standard PIC programmer.

Documentation and Source Code

Documentation

PCIM Configuration Values and Packet Summary A guide to the configuration values on the PCIM and the structure of the network packets it sends and accepts	[pdf]
PCIM LED Wiring Matrix Since the LEDs are driven in a matrixed manner, you need to know where to connect each one. From the 8 common (negative) outputs and 8 segment (positive) outputs on the MAX7219, this chart shows you how to hook up every LED (all 56 of them!).	[pdf]

Schematics

Version 1.0 Final MRB-PCIM schematic

[png]

Firmware

Version 1.0

[src] - [hex]

Photos

	MRB-PCIM Unit Prototype 20-Apr-2003 - This prototype unit, along with a twin, are in daily service inside the Wind River CTC panel	[600x400] [2160x1440]
	Installed MRB-PCIM Modules on the WRRR 20-Apr-2003 - Two finished unit installed on the Wind River Railroad CTC panel. Each controls three sidings, leaving me two empty positions for future expansion (plus, of course, the bottom two card bays that aren't wired or populated.)	[600x400] [2160x1440]