Siemens SIMATIC ET 200iSP User Manual

Purpose
You can use the diagnosis for
• checking the sensor
• to make absolutely sure that there has been a switchover between a normally open contact
and normally closed contact.
Principle
If the digital inputs of a channel group are assigned parameters as changeover contacts, the
module runs diagnostics for changeover contact sensor types for this channel group. The
tolerated changeover time between the two channels is set to the 󹪝xed value of 300 ms.
If the plausibility check is negative, then
• The module designates the value status of the normally open contact channel as invalid.
• The module creates a diagnostic entry for the NO contact channel.
• The module triggers a diagnostic interrupt.
The digital input signal and the value status are only updated for the NO contact channel
(channel 0, 2, 4, 6). For the normally closed channel (channel 1, 3, 5, 7), the digital input signal is
󹪝xed at "zero" and the value status is "invalid", as this channel is only used for plausibility
checking of the sensor.
Note the following points when carrying out a diagnosis for a changeover contact sensor type:
• If there is already an error on the normally open contact channel (a wire break, for example),
the module no longer performs diagnostics for changeover contact errors. The diagnostics
for changeover contact errors continues on the second channel.
• You will 󹪝nd additional points to note in the following table:
Table 13-7 Diagnosis for changeover contacts
Changeover contact A negative check means...
Changeover contact as NAMUR
• Short-circuit or
• Wire break
Additionally:
Changeover contact or ex‐
ternal fault (in case of DP
diagnostics)
Closed changeover contact
• Sensor defective or short-circuit
No distinction can be made here between a defective-sensor
and short circuit
Open changeover contact Caution: no di󹪜erentiation possible between
• signal "0" and wire break
• Signal "1" and short circuit
Digital electronic modules
13.1 Digital electronics module 8 DI NAMUR
ET 200iSP
304 Operating Instructions, 11/2022, A5E00247483-AK

Siemens SIMATIC ET 200iSP Specifications

General

Brand	Siemens
Model	SIMATIC ET 200iSP
Category	I/O Systems
Language	English