Internet PLC Forum

General => Technical support => Topic started by: pstiles on November 05, 2006, 06:56:03 PM

Title: ADC(8) Modbus Address
Post by: pstiles on November 05, 2006, 06:56:03 PM

Can you please tell me the Modbuss address for ADC(8). I am trying to display the value of the port on a HMI device that is conected via RE485. I can display the plc time using address's 40513-40515, but in all the paper work I have it says nothing about the addresses for ADC(1)- ADC(8).

Thanks

Title: Re:ADC(8) Modbus Address
Post by: support on November 05, 2006, 08:24:41 PM

ADC are not mapped to the MODBUS space. So you need to periodically sample read the ADC into some DM space.

E.g. every 0.5s, run the following function:

FOR I=1 to 8
   DM[I+10]=ADC(I)
NEXT

DM[11] to DM[18] will therefore contains the values of ADC#1 to #8.