Table 10-3 Signal Modules For Channel-Oriented Redundancy - Siemens SIMATIC S7-400H System Manual

Using I/Os in S7-400H
10.5 Connecting redundant I/Os
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 FAQs
at http://www.siemens.com/automation/service&support under the keyword "Redundant I/O".
Table 10-3
Module
Central: Redundant DI dual-channel
DI 16xDC 24V interrupt
Use with non-redundant encoder
•
DI 32xDC 24V
DI 32xUC 120V
Distributed: Redundant DI dual-channel
DI16xDC 24 V, interrupt
DI16xDC 24 V
Use with non-redundant encoder
•
DI16xDC 24 V
DI32xDC 24 V
DI 8xAC 120/230V
DI 4xNamur [EEx ib]
You cannot use the module for applications in hazardous areas in redundant mode.
Use with non-redundant encoder
•
•
•
134
Signal modules for channel-oriented redundancy
This module supports the "wire break" diagnostic function. To be able to use this function, make
sure that when using one and two inputs a total current between 2.4 mA and 4.9 mA flows even at
signal state "0".
You achieve this by installing a resistive load at the encoder. The value depends on the type of
switch, and usually ranges between 6800 and 8200 ohms for contacts.
For Beros, calculate the resistor based on this formula:
(30V / (4.9 mA – I_R_Bero)) < R < (20V / (2.4 mA – I_R_Bero))
This module supports the "wire break" diagnostic function. To be able to use this function, make
sure that when using one and two inputs a total current between 2.4 mA and 4.9 mA flows even at
signal state "0".
You achieve this by installing a resistive load at the encoder. The value depends on the type of
switch, and usually ranges between 6800 and 8200 ohms for contacts.
For Beros, calculate the resistor based on this formula:
(30V / (4.9 mA – I_R_Bero)) < R < (20V / (2.4 mA – I_R_Bero))
You can only connect 2-wire NAMUR encoders or contact encoders.
Equipotential bonding of the encoder circuit should always be at one point only (preferably
encoder negative).
When selecting encoders, compare their properties with the specified input characteristics.
Remember that this function must always guaranteed, regardless whether you are using one or
two inputs. Example of valid values for NAMUR encoders: for "0" current > 0.2 mA; for "1" current
> 4.2 mA.
Order number
6ES7 421–7BH01–0AB0
6ES7 421–1BL0x–0AA0
6ES7 421–1EL00–0AA0
6ES7 321–7BH00–0AB0
6ES7 321–7BH01–0AB0
6ES7 321–1BH02–0AA0
6ES7 321–1BL00–0AA0
6ES7 321–1FF01–0AA0
6ES7321–7RD00–0AB0
System Manual, 09/2007, A5E00267695-03
S7-400H