Siemens SIMATIC S7-1500/ET 200MP System Manual page 176

Properties of the front connectors
The three different front connectors are characterized as follows:
• 40 clamping points each
• Connection system: Screw terminal (for 35 mm modules only) or push-in terminal
• Module width: 35 mm or 25 mm
• If you want to supply load groups with the same potential (non-isolated), use the potential
bridges supplied for the front connector (with 35 mm width) for digital I/O modules. The
bridges are used to connect the terminals 9 and 29, 10 and 30, 19 and 39 as well as 20
and 40 facing each other. Advantage: Reduction of the wiring effort.
Note
Use of potential bridges
The use of potential bridges depends on the relevant module used.
It is not permitted to use potential bridges for 230 V modules. Use the potential bridges
only with a maximum supply voltage of 24 V DC. The current capacity per potential bridge
is 8 A maximum.
Because of the different assignment, you may not use the potential bridges with analog
I/O modules.
The front connectors for 25 mm modules have no potential bridges.
Observe the instructions and wiring rules in the product manual of the respective I/O
module when using potential bridges.
• In the delivery state a coding element is located in the module. When the front connector
is first inserted into the I/O module, a part of the coding element clips onto the front
connector. When the front connector is removed from the I/O module, one part of the
coding element remains in the front connector, and the other part remains in the I/O
module. The insertion of a front connector that is not suited to the module is thereby
mechanically prevented. This ensures, for example, that the front connector with the
coding element for a digital module cannot be inserted into an analog module.
Properties of the front connectors on fail-safe modules
In as-delivered condition, a fail-safe module not only has a mechanical coding element but
also an electronic coding element. The electronic coding key is a rewritable memory for the
PROFIsafe address. When the front connector is inserted in the F-module, the electronic
coding element engages completely in the front connector. If you remove the front
connector from the F-module, the memory with the PROFIsafe address of the fail-safe module
remains in the front connector (see section Replacing a front connector (Page 307)).
Reference
You can find additional information on the coding element in the section Coding element on
the I/O module and on the front connector (Page 303).
Additional information on the use of the potential bridges can be found in the product
manual for the respective I/O module.
Automation system
System Manual, 01/2023, A5E03461182-AK
7.10 Front connector for the I/O modules
Wiring
175