Error Responses - GE Multilin MM3 Motor Manager 3 Instruction Manual

CHAPTER 8: COMMUNICATIONS
8.2.10 Error
Responses
MM3 MOTOR MANAGER 3 – INSTRUCTION MANUAL
Slave Response
Number of setpoints
CRC
When a MM3 Motor Manager 3 detects an error other than a CRC error, a response will be
sent to the master. The most significant bit (MSB) of the function code byte will be set to 1
(i.e. the function code sent from the slave will be equal to the function code sent from the
master plus 128). The following byte will be an exception code indicating the type of error
that occurred.
Transmissions received from the master with CRC errors will be ignored by the MM3 Motor
Manager 3.
The slave response to an error (other than CRC error) will be:
Slave address: 1 byte
Function code: 1 byte (with most-significant bit (MSB) set to 1)
Exception code: 1 byte
CRC: 2 bytes
The MM3 Motor Manager 3 implements the following exception response codes.
• Exception 01 - Illegal function: The function code transmitted is not one of the
functions supported by the MM3 Motor Manager 3.
• Exception 02 - Illegal data address: The address referenced in the data field
transmitted by the master is not an allowable address for the MM3 Motor Manager
3.
• Exception 03 - Illegal data value: The value referenced in the data field transmitted
by the master is not within range for the selected data address.
SUPPORTED MODBUS FUNCTIONS
Bytes Example
2 00 02 two setpoints
2 C7 90 computed CRC error code
Description
8–11