VIPA CP 240 RS232, Manual

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Chapter 4 CP 240 - serial Manual VIPA System 200V
4-36 HB97E - CP - Rev. 11/30
With the following Modbus function codes a Modbus master can access a
Modbus slave: With the following Modbus function codes a Modbus master
can access a Modbus slave. The description always takes place from the
point of view of the master:
Code Command Description
01h Read n Bits Read n Bits of master output area 0x
02h Read n Bits Read n Bits of master input area 1x
03h Read n Words Read n Words of master output area 4x
04h Read n Words Read n Words master input area 3x
05h Write 1 Bit Write 1 Bit to master output area 0x
06h Write 1 Word Write 1 Word to master output area 4x
0Fh Write n Bits Write n Bits to master output area 0x
10h Write n Words Write n Words to master output area 4x
The description always takes place from the point of view of the master.
Here data, which were sent from master to slave, up to their target are
designated as "output" data (OUT) and contrary slave data received by the
master were designated as "input" data (IN).
System 200V
CPU CP 240 Master
System 200V
CP 240 Slave
read (01h:bit, 03h:word)
CPU
SEND FC0
RECEIVE FC1
OUT
read (02h:bit, 04h:word)
write (05h,0F:bit, 06h10h:word)
OUT OUT
Periphery
IN IN
OUT
IN
IN
0x(bit)
4x(word)
1x(bit)
3x(wort)
ANZ = number of bytes OR 4000h
ANZ < 4000h
If the slave announces an error, the function code is send back with an
"ORed" 80h. Without an error, the function code is sent back.
Coupler answer: Function code OR 80h
→
Error
Function code
→
OK
For the Byte sequence in a Word is always valid: 1 Word
High Low
Byte Byte
The shown check sums CRC at RTU and LRC at ASCII mode are
automatically added to every telegram. They are not shown in the data
block.
Overview
Point of View of
"Input" and
"Output" data
Respond of the
slave
Byte sequence
in a Word
Check sum CRC,
RTU, LRC