ABB ACS320 series, User Manual

Page: 344 / 442

344 Fieldbus control
Except where restricted by the drive, all parameters are available for both reading
and writing. The parameter writes are verified for the correct value, and for a valid
register addresses.
Note: Parameter writes through standard Modbus are always volatile, in other words,
modified values are not automatically stored to permanent memory. Use parameter
1607 PARAM. SAVE to save all altered values.
The drive supports the following Modbus function codes for 4xxxx registers:
Actual values
The contents of the register addresses 40005…40012 are actual values and are:
• Specified using parameters 5310…5317.
• Read-only values containing information on the operation of the drive.
• 16-bit words containing a sign bit and a 15-bit integer.
• When negative values, written as the two’s complement of the corresponding
positive value.
• Scaled as described earlier in Actual value scaling .
Exception codes
Exception codes are serial communication responses from the drive. The drive
supports the standard Modbus exception codes defined below.
5331 MDB DATA OUT 9
Specifies the parameter mapped to Modbus register 40088.
5332 MDB DATA OUT 10
Specifies the parameter mapped to Modbus register 40089.
Function Code Description
03 Read holding 4xxxx registers
06 Preset single 4xxxx register
16 (0x10 Hex) Preset multiple 4xxxx registers
23 (0x17 Hex) Read/write 4xxxx registers
Exception
Code
Meaning
01 Unsupported command
02 The data address received in the query is not allowable. It is not a defined
parameter/group.
03 A value contained in the query data field is not an allowable value for the drive,
because it is one of the following:
Outside min. or max. limits.
Parameter is read-only.
Message is too long.
Parameter write not allowed when start is active.
Parameter write not allowed when factory macro is selected.
Code Description