The present system:- Consists of a PLC-5/40 E CPU mounted in a 8-slot chassis. There are several remote I/O panels consisting of five 16 slot chasis (1771-A4B). Each chassis has got a 1771-ASB (remote I/O adapter) daisy chained to each other and connected to the PLC's 1B channel. The various cards already inserted (and working) in these chassis are 1771-IAD, 1771-OAD, 1771-IFE, 1771-OFE and 1771-IR. RSLogix-5 version 3.2.0.0 is used.
What we did to the existing system:- We added two(2) 1771-A3B (12 slot) chassis. Inserted several 1771-IAD and 1771-OAD. Configured them successfully. Tested the discrete I/O and found them to be okay. There were several slots vaccant in both the newly added chassis.
We started facing problems :- When we were asked to insert and configure a 1771-IFE/C module in the new 12 slot chassis. To our great dissapointment we found that although we could insert 1771-IFE/C modlues to these 12 slot chassis,we failed to correctly write the rungs for BTW and BTR. To be more specific the BTW & BTR rungs contain information regarding rack number, group number, slot number, data file etc. . To our utter dismay we found all these fields in the BTW & BTR instruction was becoming ZERO when assembled and tested. That is the rack number, group number, slot number, data file address etc. would become ZERO on being assembled. On a hunch we tried adding ANY analog module (1771-IFE or 1771-OFE or 1771-IR) to the older 16-slot chassis. To our great puzzlement the result was same ( all becomimg BTW & BTR fields becomimg zero). We have got no doubts that the data file word and control word used by us were unique and not used elsewhere.
What could have gone wrong? Any insight by experienced users would be most welcome.
Regards,
Gautam
What we did to the existing system:- We added two(2) 1771-A3B (12 slot) chassis. Inserted several 1771-IAD and 1771-OAD. Configured them successfully. Tested the discrete I/O and found them to be okay. There were several slots vaccant in both the newly added chassis.
We started facing problems :- When we were asked to insert and configure a 1771-IFE/C module in the new 12 slot chassis. To our great dissapointment we found that although we could insert 1771-IFE/C modlues to these 12 slot chassis,we failed to correctly write the rungs for BTW and BTR. To be more specific the BTW & BTR rungs contain information regarding rack number, group number, slot number, data file etc. . To our utter dismay we found all these fields in the BTW & BTR instruction was becoming ZERO when assembled and tested. That is the rack number, group number, slot number, data file address etc. would become ZERO on being assembled. On a hunch we tried adding ANY analog module (1771-IFE or 1771-OFE or 1771-IR) to the older 16-slot chassis. To our great puzzlement the result was same ( all becomimg BTW & BTR fields becomimg zero). We have got no doubts that the data file word and control word used by us were unique and not used elsewhere.
What could have gone wrong? Any insight by experienced users would be most welcome.
Regards,
Gautam