Modbus Mapping; Register Mapping - ABB ACS350 User Manual

Modbus mapping

The following modbus function codes are supported by the drive.
Read Multiple
Holding Registers
Write Single
Holding Register
Diagnostics
Write Multiple
Holding Registers
Read/Write
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. (E.g. 40102 is
parameter 0102). In this mapping, the thousands and hundreds correspond to the
group number, while the tens and ones correspond to the parameter number
within a group.
The register addresses that do not correspond with drive parameters are invalid.
If there is an attempt to read or write invalid addresses, the modbus interface returns
an exception code to the controller. See
Code
Function
Hex (dec)
03 (03)
06 (06)
08 (08)
10 (16)
17 (23)
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.
Exception codes
Fieldbus control with embedded fieldbus
on page 257.
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