How to Read the Protection Function Setting From SEPAM 20, 40, or 80 via Modbus Communication



User needs to read protection function settings from Sepam 20, 40, or 80 via Modbus communication

Product Line
Sepam series 20
Sepam series 40
Sepam series 80


It is possible for the third party software application to read the current configuration on Sepam 20, 40 and 80. PMC Modbus is used in this example to explain the method to read the configuration via Modbus Channel.

Please refer to the following procedure for reading the configuration setting via Modbus Channel

  1. Check the Function Identifier of the corresponding ANSI Protection Function. Please refer to the attachment for the information of the Function Identifier.
  2. Write the Function Identifier to the Modbus address 8321d. 
    • For example, to read the configuration of ANSI46 Negative Sequence / unbalance from SEPAM 20, the Function Code is 03 and the Unit Number is 01. Therefore, write the value 0301h into Modbus address 8321d

  3. Read the modbus address from 8193d to 8201d (9 words)
  4. The meaning of the reading value is
  • a) This protection function is enabled (Modbus Address 8194 and 8195)
    b) IDMT Curve is selected (Modbus Address 8196 and 8197)
    c) Is set Point = 48% Ib (Modbus Address 8198 and 8199)
    d) Tripping Time Delay = 160ms (Modbus Address 8200 and 8201)