IC697MDL940 Relay Output Module Troubleshooting & Light Test GE Fanuc PLC Series 90-70 MDL940

Introduction: GE Fanuc IC697MDL940 Troubleshooting Guide

This troubleshooting guide is a test of a GE Fanuc 90-70 Relay Output IC697MDL940 module in an IC697CHS750 five slot rack, with an IC697CPX772 processor and a IC697PWR711 power
supply.

Step 1: Setting Up Prophecy Machine Addition

In Proficy Machine Edition you are going to open up a test file with the same exact physical configuration as what is illustrated here in Rack 0 or Main Rack. In slot number 2 is an MDL940 configured and the processor is in run mode.
In order to accomplish this go to Target > Online Commands > Clear > Erase Controller Fault and I/O Table because this is a new request, a new configuration, and then you hit Download and Run once those are cleared you are just downloading Configuration and Logic, that’s the first two options, when it asks you what you want to download. And then of course it’s going to allow you to enabled the outputs which are illustrated here.

Step 2: The Terminal Set up

Alright, so back to the MDL940. Illustrated here is a pre-wired terminal fixture for test purposes with wires that all jump to these different terminals. The different terminals illustrated are simply anything that says V for voltage so 2, 5, 8, 11, 15 and so on. (See door card) So anything that says Voltage you need to go to the corresponding screw. Also note at the bottom of the door card 32 and 33 screws 39 and 40.
So you’ve got to make sure that these are all connected and when they are all connected what you should do is take a 24 volt DC because what you’re able to do here is 24 to 240 AC or 5 to 125 volt DC. Using test fixture,  a 24 volt power supply, enough so that when you turn on each of the relays you are able to test them and you’ve got the positive lead connected to terminal 40 and you can choose any of the terminals to have voltage going to it.
Illustrated here is terminal 40 and there is a positive lead powering all of these that are interconnected to where it says voltage. And then the negative lead is loose.

So what you are going to do there is take a test fixture, a 24 volt automobile light bulb (see above) with probes and when it’s time for test after you have turned them all on you are going to connect the negative lead from the lights to the negative lead from the power supply and then the positive lead. You are just going to do a little test here of all the different terminals once they’ve been turned on.

Step 3: Normally Open vs. Normally Closed

Okay, another thing you want to be careful about is “normally opened and normally closed.” So you have two channel A1. One of them is normally open (which will be on) and the other one is normally closed. So that means when these are not turned on, when these outputs are not turned on, then the normally open should not work.

By way of example, because you don’t want to mis-diagnose your unit.
Normally, if you open A1 which is terminal screw 1, which is right at the top right as indicated in the door card, this should not work if this is working properly so you are going to go through and test all your normally opened and all your normally closed.
Normally closed is screw 3, the next one down, so that should turn on because it’s normally closed. Terminal 4, normally open. Terminal 6, just below that normally closed and that should be on. A3 7 normally open, that’s not on, A3 normally closed number 9 that’s on. Normally open A4 screw number 10. number 12 normally closed, number 14 normally open it’s just below 12.
16 normally closed. 17 (note 16 and 17 both respond to the screws normally open), 19 normally closed this should turn on, number 20 on the left hand side normally open, 22 normally closed, 23 on the right side normally open, 25 normally closed and a couple are skipped here and you’re into the C’s C1 – C4, 28 normally open, 29 normally open, 30 normally open, 31 normally open.
So then, when you turn these on to the on position, and you hear the click, it indicates that they’re on, you should be able to get a light on. Then the other four is 35, 36, 37 and 38 all normally open should be OK.

Step 4: Go Into Output Table

You are going to go into your output table so you can test the rest. Go under default tables %Q or output. You should have yours configured so that address location starting 1 so you should hear a click and there should also be a light that comes on 1 through 4. Note you have 16 channels (see below) all together, see but A1 through A4, B1 through B4, C1 through C4, D1 through D4.

OK, you can start with your category at the top, again negative lead from the lights, negative lead from the power supply, so you can make a complete circuit. You’re going to touch both the normally open and normally closed as follows: normally open 1 should be on and then terminal 3 normally closed should be off because the switch has changed. Terminal 4 normally open is now closed, 6 normally closed should be off, 7 should be on, number 9 normally closed and should be off, 10 normally open so normally open, 12 normally closed that shouldn’t be working, 14 number fourteen is normally open now a closed circuit, 16 normally closed that’s off, 17 normally open, 19 normally closed and that’s off, 20 normally open, 22 normally closed, 23 normally open, 25 normally closed, and you are going to get into these where all 4 circuits should be on because they’re typically or normally open and you just close them as you heard the circuits closing. Alright so 28 on, 29 on, 30 on 31 on that’s right and you are going to go to 35, 36, 37 and 38 all normally open, now they should be closed. Just to reiterate one last time this can be confusing with the normally open, normally closed and sometimes it’s misdiagnosed and then they end up here and there’s really nothing wrong with them.

Step 5: Clarifying the Meaning of Normally Open & Normally Closed

Just to clarify normally open means that when the circuits are off they’re not energized, normally closed means that when these circuits are all off they are energized and they should be providing power. Just keep that in mind. Otherwise if you’re not getting a light or you’re not getting the relays in the back to click on, or if you hear them click on but you don’t have any power, or if all those work and you do have power but when you go to shut it off it won’t shut off, it sticks on, which is also no good.
Any of these things is a catastrophic problem with the device.

Tags: GE Fanuc, IC697MDL940, Troubleshooting Guide

This entry was posted on May 5th, 2015 and is filed under GE Fanuc, Troubleshooting Guide. Both comments and pings are currently closed.