PLC 2/17 1771-IFE addition

[Christoph]

I need to add an analog input to this legacy plc 2/17 system.
I placed the module in the very last slot of an 8 slot
chassi, next to an on board power supply. I have the card jumpers set for Differential current. I have the block transfers in place. I have current flow from my field sensor verified with my meter. I have tried every method I know of programming the btr and btw, even the method with the FFM. I get no data into the PLC. Any ideas I'm out of them
not sure what to do at this point

 

[Mike_RH]

Are your BTR/BTW instructions getting a DN bit?
If they are then, the instructions are working.
You should be able to get data with just a BTR, with no BTW - the data will be unscaled 0-4095 in BCD.

What type of addressing (1 slot, 2 slot or 1/2 slot)?
How do you have the BT instruction configured?
I seem to recall that the control for the BT instructions are fussy as to where they can be placed - first T/C addresses I think.

 

[Christoph]

The logic is at the very begining starting at rung 0.
I believe the system is set up for 2 slot addressing.
the config is set up for 4-20mA. and 2's compl. integer.
And I am getting done bits from the block transfers.

 

[Mike_RH]

If you are getting done bits on the read, the transfer is working. If the data is not correct, then the BTW data is not correct.
The position of the rungs don't matter, but I am pretty sure the control address of BT instructions do.
Try just a BTR with no BTW and see what you get for data, you will have to cycle power to clear the configuration you have already loaded into the IFE with the BTW.

 

[Christoph]

I just picked open addresses in the 600 and 700 range
with no rime or reason, as this will become ControlLogix
remote I/O in another 8 months but I need this input now for
redundant position feedback because of percieved safety issues.

 

[Mike_RH]

Check out appendix C of this manual http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1771-um663_-en-p.pdf
Also page 3-2 of the same manual for sample PLC-2 code that works, see rungs 6 and 7.

Post a screen shot of your rungs if you can.

 

[Christoph]

That link to the manual is the same PDF I have been
Working with. My rungs are almost identical I
Have left out the manual push button trigger.
I am using a dos software to pgm with but will try
And post a snapshot Monday.

 

[Mike_RH]

Again, what addressing is being used in the chassis ( 1, 2 or 1/2 slot)?
What is the data address being used? Is the data address consecutive to any other block transfer data addresses?
If these are the only block transfer instructions, the data address must be the first available T/C addresses.
The data address also uses the address 100 octal higher. That isnifmyour data address is 030, address 130 is also used.

 

[RussB]

IIRC, the 217 had EEPROM that stored the logic, if I'm correct don't forget to update it.

 

[Christoph]

Ok found the issues. Noticed when powering up (with no battery in the PLC
so no program when starting), the green lights on the IFE card were not flashing but steady. The card was defective, and second I had a 16 point input card beside the module in the same module group, in my test rig. Pulled that out and the card is working.