Absolute encoder on AB SLC5/04

I am in need to use an absolute encoder on SLC5/04.

We have some classic PLC5/25 with absolute encoder and uses a latching input module to interface.

For SLC what is my options.

Thank You

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What is it that you need exactly?

I am in need to use an absolute encoder on SLC5/04.

Click to expand...

So, what is stopping you from using an absolute encoder with the 5/04?

We have some classic PLC5/25 with absolute encoder and uses a latching input module to interface.

Click to expand...

A latching input module? Just what is that? A part number would helpful. I bet it is a 1771-XXXX number.

For SLC what is my options.

Click to expand...

Same as above. The encoder provides information about the rotation of an object. That information is presented in any of several ways. If you use the encoder you currently have, match the encoders output with the proper input module for the SLC family. Given practically no information to go on from your post, this is the best advice I can offer at this time.

I suppose that chavak is using a 1771-DS DC latching input module, or a 1771-DL Gray Encoder input module. The -DS module was specifically built to "latch" short input pulses that the PLC I/O scan could not catch.

In the SLC-500, the I/O and logic scan is much faster than the PLC-5/25 and usually a standard DC input module is used. There are RA Knowledgebase documents that illustrate how to decode the gray code signals in ladder logic.

You might also be able to set up a Discrete Input Interrupt routine in the SLC just for this module. I am not very familiar with that function in the SLC so I will just advise you to read that chapter of the User Manual.

If you havent purchased an encoder yet then AB offers several options:
The 842A with and interface from AMCI can offer Grey code or natural numbers.
http://www.ab.com/sensors/products/encoders/bulletin842a.html

http://www.amci.com/plc-modules/plc_modules_abslc500.7500.asp

There is also a DeviceNet option, 842D:
http://www.ab.com/sensors/products/encoders/index.html

Hi Randylud,

Sorry for not being more specific in my question. As what Ken mentioned the PLC5/25 was using a Gray Encoder. The machine was mechanical cam based driven by a single shaft linking to about 20 stations through cam followers/linkages. The encoder gives a position of the cam which translated as position reference for the program so the actuators can react.

I am away from work and I can't confirm the latching input module, If I am not wrong it is as Ken mentioned a 1771-DS. I will browse through the RS Knowledge base.

Thank You Ron for the links. In the current project there is a requirement to use an absolute encoder on SLC platform, which I have not done before.

It is not on Devicenet.

Thank You