TI-545 Question

I am programming a PV+1250 to a TI545-1102, I am using bit of word instruction variables in some places e.g. V177.5 to set a function from the OIT.

While monitoring the program using TI-Soft ver 7.1 I cannot see the bit change in the ladder logic, but when I monitor the word value, I see it change.

Is this just a bug in the software or what?

One thing to keep in mind is that TI uses bits 1 to 16, not 0 to 15.

That's right, and the MSB is bit 1

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 ---TI bit format
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 ---Allen Bradley and others.
M
S
B

I already know that, thanks.

The question is, when I have a N.O. contact on the ladder which is controlled from the PV+ I do not see the bit change state on the ladder, but I see the integer register change value.

What we are trying to say is that the bit you think you're changing in the panelview may not be the bit that's actually being changed in the PLC. When you toggle the bit how much does the integer value change, does it correspond with the weighted value of the desired bit? In your first post you listed V177.5 if you have the correct bit mapping, then your integer value should change by 2048, does it?


I have several 505 PLC's connected to SCADA's and when you toggle a bit in the SCADA you can see it in TiSoft. So there's not a bug in the software.