AB Flex I/O 1794-AFB

Ok, to day I ran into a new device that I have never worked with before and wss hoping for some assistance. I was asked to incorporate an audible alarm into an exsisting system. The system has a flow meter in line with a diaphragm pump and what they want to do is turn an alarm on if the pump fails for some reason or another. I do not think this will be a problem other than the fact I have never dealt with Flex I/O and the flow meter is wired to the Flex I/O. Has anyone dealt with these and if so can I get some pointers and an Idea on the operation of the Flex. How does the addressing work? And does it connect to a PLC that executes the code for the Flex?

Could the device you're looking at be a 1794-APB Profibus DP adapter ? I have never heard of a 1794-AFB, though I have not seen everything.

The I/O modules themselves will have different part numbers. A flowmeter is probably connected to a counter-type module like a 1794-IJ or -IK, or even a high-speed counter 1794-VHSC.

You're going to have to follow the wire back from the FLEX network adapter to whatever it's connected to to find out what sort of controller is being used.

Thanks for the reply

Sorry for the Typo, I believe that is 1794-ASB and the modules are
1794-IR8
IB16
OB16

There is a Direct Logic 205 in the same cabinet, but there is also a PLC5 in a different cabinet as well, both go the same equipment.

Just how would the Flex I/O be connected to the PLC? I did not see any ethernet connected to the Flex, then again none that I noticed anyway. once I identify the PLC how can I tell the addressing for the Flex?

A 1794-ASB is an Allen-Bradley Remote I/O adapter; 'Remote I/O' being the AB proprietary I/O network, not a generic term. You should see a two-conductor cable, typically blue, connected to the adapter. This will be connected to a three-pin connector on the PLC5, probably labelled 'B'.

If you get a manual for the 1794-ASB you will be able to decipher the rack address and possible starting group from the ASB DIP switch settings. The 1794-IR8 will be accessed using a block transfer read (BTR). The other two modules will show up in the I/O immage table at the appropriate location.

You need to be aware of both the rack address and the starting group. The starting group is like an offset into the rack. If the starting group is 0, for example, then the IR8 will be at group 0 and the other modules will follow it. If the starting group is 4 the IR8 will be at group 4 and the other modules will follow it.

I hope this helps.
Keith

Thanks that gives me a real good starting point... I will look into it more when I get back to the plant.

If you are using 1794-ASB/E use the manual
http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1794-um009_-en-p.pdf


If you are using 1794-ASB/D & lower use the below manual

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1794-um003_-en-p.pdf

rPraveenkum said:

If you are using 1794-ASB/E use the manual

If you are using 1794-ASB/D & lower use the below manual

Click to expand...

How can I tell if I have an E or D? The numbers that are on the module does not specify.

You will have to remove it from service, the info you require is usually not visible from the front of the module.

Ah... I see, thanks for the insight.