Galil Motion Control RIO-47120, Руководство пользователя

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Function Code 16 ($10) – Write Multiple Registers
Description
Modbus function code ($10) is a request to write multiple registers, also known as analog outputs
Operating as a master
The function code of the response can be queried with the _MW command. If an exception occurred, the
exception code of the response can be queried with _MW1.
Example:
Normal Response Exception Response
_MW results in $10 _MW results in $90
_MW1 contains $01 or $02
Ways to use function code 16 with Galil commands:
1. MB command in raw packet mode
2.
MB command with Modbus function code 16
3. AO[x] See command reference for details
Note: The RIO acting as a master can write up to 123 registers at a time with function code 16 per the
Modbus specification.
The Modbus transaction results are available with the _MW and _MW1 commands.
Operating as a slave
The RIO will accept different starting address ranges for a write multiple registers request depending on the
state of the MI command. If MI is set to 0 (register data is volts in 32-bit floating point), the RIO will accept
an address range of $0001-$000E. If MI is set to 1 (register data is count in 16-bit decimal), the RIO will
accept a write multiple registers request with an address range of $0000-$0007. The RIO will respond with
function code 16, a 2 byte starting address field identical to the starting address field of the request packet,
and a 2 byte quantity of registers field identical to the quantity of registers field of the request packet.
RIO-47xxx Chapter 3 Communication ● 35