Adding PLC5 module to ControlLogix.

We have a controllogix setup with 3 racks, and 14 racks of PLC5 using RIO cards.

Here is my question.

One of the PLC5 racks has a analog output card that isnt being used, and isnt listed in the hardware tree inside of Rslogix 5000. When I right click to add a new module the option is grayed out.

Im still green at all of this. Any suggestions will be greatly appreciated.

Is that while you are online or offline?

Are you using a 1756-DHRIO, or a 1756-RIO ? With 14 chassis worth of that legacy stuff it's just within the scope of what the 1756-DHRIO can handle, but the 1756-RIO was built specifically to handle non-trivial RIO scanner projects because you quickly max out a controller's buffers with more than a handful of analog modules.

In general, the old RIO interfaces with 1771 can't be modified in RUN mode like some modern ControlNet or EtherNet/IP with 1756.

I would have to dust off some stuff to see whether there was even an analog module object you could point at with the 1756-DHRIO's scanlist applet, or if you just had to write MSG instructions to perform the duties of the BTR/BTW block transfers to that logical Rack/Slot/Group number.

I have tried this online, and offline, and i still get the option to add a module grayed out.

I am using a 1756-DHRIO. We use 3 of these DHRIO cards in our Local rack, so the 14 chassis are spread out across those 3 cards.

We have some analog inputs and outputs from other PLC5 cards, and we dont have any BTW/BTR in our logic, im thinking we just use MOV's.

Look for MSG instructions, they replace the legacy BTW/R function.

yes, you are right. Im not sure why i said MOV's.

We have MSG instuctions with the Message Control with "R6G3M0_IFE_Read"


So, i know how to address these modules, just not sure how to add one. I guess Ill just try to take the processor out of run mode, and see if that would allow me to add it.

Thanks for the help.

HoldenC, when I've done our PLC5 to Logix conversions with 1756-DHRIO modules, I added the 1771-ASB into the I/O Configuration tree but not the individual I/O modules. I believe this setup is called "rack optimized" so that if you configure the ASB for a full rack, the program creates a tag array of 8 INTs each for inputs & outputs. We use MSG instructions to handle our block transfers to analog modules.

You should be able to add MSG instructions for Block Transfers to the new module but you will have to power down the rack to install the new card.

The module has actually been in the rack since 2013, it just has no logic referencing that card.

With the card already installed, I should be able to just write the MSg instruction for the card and start using it ?

I don't see why not. What module are you working with?

First thing I would do is make sure your block transfers are properly set up for that particular module (download a PDF manual from Rockwell if you don't already have one). Then I would test out the block transfers without adding any control logic. Once you're satisfied that you're getting good data, add the logic.

One caveat I'd add is that most likely, your read/write data will be in 16-bit INT format, not 32-bit DINT.