Modbus Mapping; Register Mapping - ABB ACS355 User Manual

312 Fieldbus control with embedded fieldbus

Modbus mapping

The following Modbus function codes are supported by the drive.
Function Code
hex (dec)
Read Multiple 03 (03)
Holding
Registers
Write Single 06 (06)
Holding
Register
Diagnostics 08 (08)
Write Multiple 10 (16)
Holding
Registers
Read/Write 17 (23)
Multiple
Holding
Registers

Register mapping

The drive parameters, Control/Status word, references and actual values are mapped
to the area 4xxxx so that:
• 40001...40099 are reserved for drive control/status, reference and actual values.
• 40101...49999 are reserved for drive parameters 0101...9999 (eg 40102 is
parameter 0102). In this mapping, the thousands and hundreds correspond to the
Additional information
Reads the contents of registers in a slave device.
Parameter sets, control, status and reference values are mapped
as holding registers.
Writes to a single register in a slave device.
Parameter sets, control, status and reference values are mapped
as holding registers.
Provides a series of tests for checking the communication between
the master and the slave devices, or for checking various internal
error conditions within the slave.
The following subcodes are supported:
00 Return Query Data: The data passed in the request data field is
to be returned in the response. The entire response message
should be identical to the request.
01 Restart Communications Option: The slave device serial line
port must be initialized and restarted, and all of its communication
event counters cleared. If the port is currently in Listen Only Mode,
no response is returned. If the port is not currently in Listen Only
Mode, a normal response is returned before the restart.
04 Force Listen Only Mode: Forces the addressed slave device to
Listen Only Mode. This isolates it from the other devices on the
network, allowing them to continue communicating without
interruption from the addressed remote device. No response is
returned. The only function that will be processed after this mode is
entered is the Restart Communications Option function (subcode
01).
Writes to the registers (1 to approximately 120 registers) in a slave
device.
Parameter sets, control, status and reference values are mapped
as holding registers.
Performs a combination of one read operation and one write
operation (function codes 03 and 10) in a single Modbus
transaction. The write operation is performed before the read
operation.