cp1l-e and HBM rs485 load cells

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hi folks new to the forum and a bit of a jack of all trades in the engineering industry (Mainly control)  unfortunately my role sometimes and now becoming more frequent involves shall we say some more in depth programming which is eating up a lot of time and resources due to my incompetence !!

my latest project involves the use of HBM digital load cells (FIT7A) which are 485 and im using a cp1l-e .

I am just asking the question if anyone here has any experience with the hbm cells and the ascii commands used etc to interface with them or any others for that matter.

Ive never had to use the txd rxd commands etc previously, the only time ive ever used 485 before I implemented a downloadable function block to talk to Omron mx2 inverters so my input was very limited.


any help would be greatly appreciated

thanks in advance


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Welcome to the forum.

Here is a link to a quick start for TXD / RXD instructions.

Fairly straight forward instructions to use.  Just remember the transmitted and received data will be in HEX.

I have NO experience with the HBM load cell.  I would think they should have documentation for the comms sequence.

Hope this will help.

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I hope the HBM load cell does not use very deep ASCII commands. I just finished an ASCII project with a different device, and it was originally specified for CP1H, which does not support STRING data type (neither does CP1L/E). Here's an example of the message exchanges required to get a measurement value from the device:


Because of this, especially that long string "D/KS....." which needed to be examined and values parsed out, the project quickly became very complicated and difficult without STRING data type. I had to change the PLC spec to CJ2M in order to meet the deadline.

 If your load cell is just sending you a number it should be easy enough, but if requires a whole conversation to coerce a value out, or it's sending something like above, consider doing something else.

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