Hi all, looking for some suggestions or experience with following issue:
First you should know that the equipment I have here is about 30 years old however having said that, it is quite robust and does a fine job for the application for the time being.
I have an absolute encoder that gives a 4 X 4 bit BCD output.
Presently it inputs to a purpose built positioning card which looks after setpoint/actual values and basic digital control signals which in turn are used by a controller for positioning.
I am upgrading the control system to Siemens S7-300 and at a later date the encoder system will be replaced by drives/encoders. However at this time I want to use the existing encoder signal and do the control in the PLC.
So I need to bring the BCD 4 bit value (that’s 4X4 – 16 points) into the PLC.
My questions are (yes finally I have one!)
Well sorry for the long story, any comments appreciated
First you should know that the equipment I have here is about 30 years old however having said that, it is quite robust and does a fine job for the application for the time being.
I have an absolute encoder that gives a 4 X 4 bit BCD output.
Presently it inputs to a purpose built positioning card which looks after setpoint/actual values and basic digital control signals which in turn are used by a controller for positioning.
I am upgrading the control system to Siemens S7-300 and at a later date the encoder system will be replaced by drives/encoders. However at this time I want to use the existing encoder signal and do the control in the PLC.
So I need to bring the BCD 4 bit value (that’s 4X4 – 16 points) into the PLC.
My questions are (yes finally I have one!)
- Is my only option to connect directly to digital Inputs?
- Does Siemens have some sort of FM module to handle BCD IN?
- If using inputs, when I read the input word (L IW3) what will I get? A decimal Integer or BCD or what?
- Does anyone know of a BCD to Profibus (or other protocol) signal converter, perhaps Phoenix Contact? Thinking of a Din rail mount thing.
- If using PLC inputs, will they be fast enough? (I know you can’t really answer that one without knowing the application and specs but I though I would throw that in just in case someone has tried something similar with or without success!)
Well sorry for the long story, any comments appreciated