Analog Inputs

Great site lots of info
I have a AB 5/40 plc with lots of remote i/o. I am trying to hook up a rtd to an analog input card. How do I find where that input is in the plc not so sure where to look. The address would be like AI-026h-08 but which resgester to look in ie n12:90 any easy ways to find out
thanks for any suggestions

I:S.W/B

I - Input File
: - File Separator
S - Slot
. - Word Separator
W - Word (16-bit)
/ - Bit Separator
B - Bit

Since you are looking for ANALOG value, don't use bit address.

For examplle
I:4.1 is input for card in slot 4 and second input

Panic Mode almost got it correct for discrete I/O but forgot the Rack Number.
The correct configuration is

I:RG/B or O:RG/B

Where I or O = Input or Output
R = Rack Number
G = Group (Slot) Number
B = Bit Number

However, Analog Modules use Block Transfers to send the data to the data table. If the Analog Module already exists, search the program for a Block Transfer Read (BTR) instruction which has the Rack and Group Number of the module in question. The Data File Address in the BTR will tell you where the data is put into the Data Table and the Length will be the number of words of data transferred. If you are using RSLogix 5 you can double click on Setup Screen at the bottom of the BTR instruction and determine the exact address of the data for the analog I/P you are using or consult the documentation for the analog module. You may also have to change the configuration of the module to configure it for your new RTD. This is in the data sent to the module with a Block Transfer Write (BTW) instruction.

If you need more help, send more details.

Vic said:

Analog Modules use Block Transfers to send the data to the data table.

Click to expand...

Unless it is mapped IO like Control Net, then it would be closer to what Panic Mode suggested. For Remote I/O, Vic is right - look for your BTR and BTW instructions.

Marc