ProSoft Technology BM-1000-PM1K - Manual (Page 32)

Diagnostics
Page 32 of 36 ProSoft Technology, Inc.
June 10, 2015
2. I/O LED (Right):
a. Green: USB enabled
b. LED not on: No power
i. Connect USB to PC first, then to I/O Expansion Module.
ii. Verify unit is powered on, Power LED (left) should be red.
iii. Verify the PC is on.
3. Unable to Read/Write Modbus Values
a. Verify that the Modbus slave ID is the Module ID + 1
Example: If the Module ID is 0, the Modbus slave ID will be 1
b. Select MSB first when applicable when setting up Modbus Master device.
c. Verify Modbus RS485 wiring (3-wire).
d. Verify baud rate, data bits, parity, and stop bits (9600 / 8 / None / 1).
e. Refer to Modbus Mapping (page 27).
i. Verify the Modbus function code.
ii. Verify the Modbus register address.
iii. Verify the data type (integer/float, 16/32 bit).
iv. Verify if address has read/write or only read function capabilities.