Siemens AS 235 appendix Modules from other systems, Selection criteria for I/O modules

This catalog is out of date, see note on page 1

I/O modules

Summary

I/O modules from other systems

I/O modules from other systems can be operated on the I/O bus of an AS 235 automation system via existing parallel and serial links (see Section 7).

The following modules can be connected:

•SIMATIC S5-115U digital and analog input/output modules, fit- ted in ER 701-1 and ER 701-2 expansion racks

•SIMATIC S5-135U/155U digital and analog input/output mod- ules, fitted in EU 183U, EU 184U and EU 187U expansion units

•Digital and analog input/output modules of the ET 100U elec- tronic terminator

The respective interface module for the coupling occupies one I/O slot.

These modules are addressed via the driver blocks for analog and binary input/output which are present as standard in the AS 235 automation system. The analog drivers are equipped with special, parameterizable operating modes for SIMATIC S5 modules. Limit monitoring functions in the driver software are used for measured-value monitoring functions which are miss- ing on the SIMATIC S5 modules or which operate with limits other than those common in the TELEPERM M system.

Communication between TELEPERM M and SIMATIC S5/S7 automation systems is possible using the coupling module 6DS1 333-8AB (page 7/8) and the 3964 R/RK 512 procedure.

Selection criteria for I/O modules

There are various criteria for selecting the most suitable I/O mod- ules for a particular application; these criteria must be evaluated depending on the respective application. The selection of either TELEPERM M or SIMATIC S5 modules is made easier for the planning engineer by the following decision criteria:

•Preprocessing on the module

Only signal modules from the SIMATIC S5 range without pre- processing (non-intelligent) can be used.

•230 V peripherals

In contrast to TELEPERM M, the range of SIMATIC S5 modules also contains input/output modules for signals up to 230 V.

•Backup response

In the event of a fault in the automation system, a fault in the coupling, or faults in the expansion unit, SIMATIC modules always enter the safety status (0 V, 0 mA), whereas the plan- ning engineer can select for the TELEPERM M output modules whether the last value is to be retained or whether the safety value is to be output.

•Transmitter and measuring range monitoring

The monitoring functions for measuring range limits which are not present in the SIMATIC S5 modules to the same extent as in the TELEPERM M modules are implemented in the special operating modes of the driver blocks in the automation system so that they are also available when using SIMATIC S5 mod- ules.

Power supply, earthing

The different earthing concepts of the two systems must be observed when using TELEPERM M automation systems and SIMATIC S5 expansion units together. An automation system is always part of a so-called "0-V island" which is earthed via a sin- gle connection to the central earthing point (with the central 24-V supply). In the SIMATIC S5 expansion unit, the M potential of each module is directly connected to the frame and via this to the local earth.

In the case of coupling between TELEPERM M automation sys- tems and SIMATIC S5 expansion units, it must be ensured that the screen of the connection cable does not destroy the earthing concept of TELEPERM M. Isolating power supply units must be used in the expansion unit, or DC 24 V/DC 24 V converters with electrical isolation must be provided if necessary.

Lightning protection with distributed configuration

The use of SIMATIC S5 modules in distributed, serially-coupled EU expansion units makes it possible to protect the transmission lines using appropriate overvoltage arresters.

4/4 Siemens PLT 111 · 1999