Signal Modules For Redundancy; Table 13- 3 Signal Modules For Redundancy - Siemens SIMATIC S7-400H System Manual

13.4.1

Signal modules for redundancy

Signal modules as redundant I/O
The signal modules listed below can be used as redundant I/O. Refer to the latest
information about the use of modules available in the readme file and in the SIMATIC FAQ at
http://www.siemens.com/automation/service&support under the keyword "Redundant I/O".
Take into account that you can only use modules of the same product version and same
firmware version as redundant pairs.
Table 13- 3 Signal modules for redundancy
Library V5.x Library V4.x Library V3.x Module
Central: Redundant DI dual-channel
X
X
X
Distributed: Redundant DI dual-channel
X
X X
S7-400H
System Manual, 03/2012, A5E00267695-11
X DI 16xDC 24V interrupt
Use with non-redundant encoder
This module supports the "wire break" diagnostic function. To implement this

function, make sure that a total current between 2.4 mA and 4.9 mA flows
even at signal state "0" when you use an encoder that is evaluated at two
inputs in parallel.
You achieve this by connecting a resistor via the encoder. Its value depends
on the type of switch and usually ranges between 6800 and 8200 ohms for
contacts.
For BEROS, calculate the resistance based on this formula:
(30 V/(4.9 mA – I_R_Bero) < R < (20 V/(2.4 mA – I_R_Bero)
X DI 32xDC 24V
X DI 32xUC 120V
X DI16xDC 24 V, interrupt
X DI16xDC 24 V
In the event of an error on one channel, the entire group (2 channels) is
passivated. When using the module with HF index, only the faulty channel is
passivated in the event of a channel error.
Use with non-redundant encoder
This module supports the "wire break" diagnostic function. To implement this

function, make sure that a total current between 2.4 mA and 4.9 mA flows
even at signal state "0" when you use an encoder that is evaluated at two
inputs in parallel.
You achieve this by connecting a resistor via the encoder. Its value depends
on the type of switch and usually ranges between 6800 and 8200 ohms for
contacts.
For BEROS, calculate the resistance based on this formula:
(30 V/(4.9 mA – I_R_Bero) < R < (20 V/(2.4 mA – I_R_Bero)
13.4 Connecting redundant I/O to the PROFIBUS DP interface
Using I/Os in S7–400H
Order number
6ES7 421–7BH0x–0AB0
6ES7 421–1BL0x–0AA0
6ES7 421–1EL00–0AA0
6ES7 321–7BH00–0AB0
6ES7 321–7BH01–0AB0
187