Emerson PACSystems RX3i - RTU Message Descriptions; Figure 23: RTU Read Output Table Message Format

PACSystems™ RX3i and RSTi-EP CPU Reference Manual Section 6
GFK-2222AK October 2019
Serial I/O, SNP & RTU Protocols 170
18-21
Not Defined
Not Defined
22
Mask Write 4x Registers
8
8
23
Read/Write 4x Registers
13+byte 11
76
5+byte 3
76
24–66
Not Defined
Not Defined
67
Read Scratch Pad
6
3 + 3rd byte
76
68-127
Not Defined
Not Defined
128-255
Not Defined
3
6.3.3 RTU Message Descriptions
This section presents the format and fields for each RTU message.
6.3.3.1 Message (01): Read Output Table
6.3.3.1.1 Format:
Figure 23: RTU Read Output Table Message Format
Address
Starting
Point No.
Number of
Points
Error
Check
Func
01
Query
Hi
Hi
Lo
Lo
Address
Data
Error
Check
Func
01
Normal Response
Byte
Count
6.3.3.1.2 Query:
An address of 0 is not allowed because this cannot be a broadcast request.
▪ The function code is 01.
▪ The starting point number is two bytes in length and may be any value less than the
highest output point number available in the attached CPU. The starting point
number is equal to one less than the number of the first output point returned in the
normal response to this request.