Siemens bt300 Operator's Manual page 149

Example 2
Read the Process Data 42103 through 42104 with command 4 (Read Input Registers).
ADDRESS
FUNCTION
DATA Starting address HI
Starting address LO
No. of registers HI
No. of registers LO
ERROR CRC HI
CHECK CRC LO
Message frame:
The reply to the Read Input Registers message contains the values of the read registers.
Answer Slave - Master:
ADDRESS
FUNCTION
DATA Byte count
Data HI
Data LO
Data HI
Data LO
ERROR CRC HI
CHECK CRC LO
Reply frame:
Example of an exception response
In an exception response, the Slave sets the
an exception code in the data field.
Command Master - Slave:
ADDRESS
FUNCTION
DATA Starting address HI
Starting address LO
Siemens Industry, Inc.
Building Technologies
Command Master - Slave:
01 hex Slave address 1 hex (= 1)
04 hex Function 4 hex (= 4)
08 hex
36 hex
00 hex Number of registers 0002 hex (= 2)
02 hex
93 hex CRC field 93A5 hex (= 37797)
A5 hex
01 04 08 36 00
01 hex Slave address 1 hex (= 1)
04 hex Function 4 hex (= 4)
04 hex Byte count 4 hex (= 4)
13 hex Speed reference = 1388 hex (= 5000 = > 50.00%)
88 hex
09 hex Output Frequency = 09C4 hex (= 2500 = >25.00 Hz)
C4 hex
78 hexCRC field 78E9 hex (= 30953)
hex
01 04 04 13
most-significant bit (MSB)
01 hex Slave address 1 hex (= 1)
04 hex Function 4 hex (= 4)
17 hex Starting address 1770 hex (= 6000)
70 hex
Siemens BT300 HVAC Drive
Chapter 4 - Parameters and Menu Structure
02 93 A5
88 09 C4 78
of the function code to 1. The Slave returns
I/O and Hardware (M5)
E9
DPD01809
2016-06-07
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