Can not change the set-point on CM30 from labview
I am using Labview to control a cm30 using Modbus Ethernet, I am able to read the values for the PV,Output and setpoint, but a can’t seem to write to the setpoint.
Is there another Modbus register which I need to write to first which will then allow me to change the setpoint value?
The setoint changes from the controller, and as I mentioned above I am able to read the value so am confident I have the correct registers.
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Apologies for the late reply, I am currenly travelling in the USA and so am a little behind in time. Sumit has sent you the register addresses but has failed to disclose an important point. Those addresses are for the local setpoints they are not for the actual currently used setpoint. This is a diferent register. What versioo software do you have in he instrument? I can send you a complete modbus register listing but you must have up to date software in order for it to be effective. Can you please advise your email address s I can send it to you directly.
It depends which setpoint for which loop your are reading/writing, it's same register for reading and writing setpoints, use these register addresses.
Check this thread for modbus registers addresses of SLC's, @ http://www402.abbext.com/I-address-ControlMaster-CM30-modbus-address-q315330.as
Reply back if you have any issue in reading those registers