Function 16: Preset Multiple Register; Modbus® Ascii Protocol - Siemens ATC5300 Manual

General Information

1.11 Function 16: Preset Multiple Register

1.11 Function 16: Preset Multiple Register
This function allows to modify multiple parameters with a single message, or to preset a value
longer than one register. The address and the valid range for each parameter are stated in
Table 3.
Master message:
Slave address
Function
MSB register address
LSB register address
MSB register number
LSB register number
MSB data
LSB data
MSB data
LSB data
MSB CRC
LSB CRC
Slave response:
Slave address
Function
MSB register address
LSB register address
MSB byte number
LSB byte number
MSB CRC
LSB CRC
1.12 Modbus
®
The Modbus® ASCII protocol is normally used in application that require to communicate
through a couple of modems. The functions and addresses available are the same as for the
RTU version, but the transmitted characters are in ASCII and the message end is delimited by
carriage return / line feed instead of a transmission pause.
If one selects the parameter P7.04 and / or P7.07 as Modbus® ASCII protocol, the
communication message on the correspondent communication port has the following
structure:
• The Address field holds the serial address of the slave destination device.
• The Function field holds the code of the function that must be executed by the slave.
• The Data field contains data sent to the slave or data received from the slave in response
to a query. The maximum allowable length is of 60 consecutive registers.
• The LRC field allows the master and slave devices to check the message integrity. If a
message has been corrupted by electrical noise or interference, the LRC field allows the
devices to recognize the error and thereby ignore the message.
• The message terminates always with CRLF control character (0D 0A).
12
ASCII Protocol
Address
:
(2 chars)
08h
10h
20h
01h
00h
02h
06h
F4h
06h
83h
55h
3Ah
08h
10h
20h
01h
00h
04h
9Bh
53h
Function Dates
(2 chars) (N chars)
Modbus Communication Protocol, Edition 03/2011, A5E02469001-02
LRC (2 chars) CR LF
ATC5300