How To Select The Appropriate Modbus Block - Siemens SIMATIC S7 Manual

3.4

How to Select the Appropriate Modbus Block

General
Information
Which CPs
support
AG_CNTRL?
OPEN MODBUS / TCP communication via CP343-1 and 443-1
2XV9450-1MB00; Manual edition 4.3
The block FC10 AG_CNTRL of the SIMATIC_NET library permits to terminate
and reestablish an established connection. This block was also implemented
in the Modbus blocks for a more effective use of the resources of CPU and
CP. However, previous CPs or previous firmware releases do not support the
use of AG_CNTRL.
Therefore the library contains directories for both alternatives, each for
S7-300 CPs and S7-400 CPs:
•
Current CP 300
•
Current CP 400
•
Previous CP 300
•
Previous CP 400
Pay attention to the count of local data of the used CPU! The required
local data for both alternatives are written in chapter 5.4.
Here you can find up-to-date information which CPs and which firmware
releases support AG_CNTRL:
Ethernet CPs and AG_CNTRL
If the used CP is not mentioned here, the Modbus blocks without AG_CNTRL
must be used.
CPs of S7-300 which support AG_CNTRL
(not for CPU315 and 317 HW release V1)
CPs of S7-400 which support AG_CNTRL
CPs of S7-300 which do not support
AG_CNTRL
CPs of S7-400 which do not support
AG_CNTRL
Commissioning
3-9