Digital Electronic Modules
11-40
ET 200S Distributed I/O System
EWA-4NEB 780602402-12
Diagnostics with the changeover encoder type
With the diagnostic functions for the changeover encoder type, the digital
electronic module monitors the changeover between two input channels. If there is
no signal transition at the NC contact when the specified changeover time (see
technical specifications) has expired, the module outputs diagnostics information.
Purpose
You can use the diagnostics function to
S
analyze the encoder
S
verify that the switch has changed between the NO contact and the NC contact.
Principle
If the digital inputs of a channel group are configured as ”changeover contacts”, the
module for this channel group carries out a diagnostics for the changeover contact
type of sensor. The tolerated changeover time between the two channels is set to
the fixed value of 300 ms.
If the plausibility check returns a negative result,
S
The module identifies the value status of the normally open contact channel as
”invalid”.
S
The module creates a diagnostic entry for the normally open contact channel.
S
A diagnostics interrupt is triggered.
The digital input signal and the value status are updated only for the NO channel
(channel 0, 2). For the NC channel (channel 1, 3), the digital input signal is set to
the fixed value ”zero,” and the value status is ”invalid” because this channel is used
only for the validation of the sensor.
Note the following points in the diagnosis for the changeover contact type of
sensor:
•
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. Changeover errors are still monitored on the other channel.
•
You will find further details in the table below:
Table 11-16 Changeover Contact Diagnostics
Changeover contact
Negative check means ...
Changeover switch as
NAMUR
•
Short-circuit or
•
Wire break
Also:
Changeover error or
t
l
(i DP
changeover switch with
load resistance
•
Sensor defective or short-circuit
No distinction between a defective sensor and
short-circuit is possible.
external error (in DP
diagnostics)
changeover switch without
R-circuit
Important: no differentiation possible between
•
”0” signal and wire break
•
”1” signal and short-circuit
Содержание SIMATIC ET 200S
Страница 42: ...Product Overview 1 16 ET 200S Distributed I O System EWA 4NEB 780602402 12 ...
Страница 64: ...Brief Instructions on Commissioning ET 200S 2 22 ET 200S Distributed I O System EWA 4NEB 780602402 12 ...
Страница 112: ...Configuration Options 3 48 ET 200S Distributed I O System EWA 4NEB 780602402 12 ...
Страница 232: ...Commissioning and Diagnostics 6 72 ET 200S Distributed I O System EWA 4NEB 780602402 12 ...
Страница 244: ...General Technical Specifications 7 12 ET 200S Distributed I O System EWA 4NEB 780602402 12 ...
Страница 274: ...Interface Modules 8 30 ET 200S Distributed I O System EWA 4NEB 780602402 12 ...
Страница 538: ...4 IQ SENSE 13 18 ET 200S Distributed I O System EWA 4NEB 780602402 12 ...
Страница 564: ...Address Space of the Input and Outputs of the ET 200S C 4 ET 200S Distributed I O System EWA 4NEB 780602402 12 ...
Страница 574: ...Response Times D 10 ET 200S Distributed I O System EWA 4NEB 780602402 12 ...
Страница 580: ...Special Measures for Interference Free Operation F 4 ET 200S Distributed I O System EWA 4NEB 780602402 12 ...
Страница 600: ...Product Information on the Use of subassemblies modules in a Zone 2 Hazardous Area 2 A5E00352937 02 ...