Mitsubishi MELSEC-WS series, User Manual

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Chapter 3
40
Product description
3.9 WS0-XTDI safety input module
3.9.1 Description
The WS0-XTDI module is the input extension with 8 safe inputs. It offers the following
functions:

monitoring of the connected sensor equipment, also refer to Chapter 4.
 passing the input information to the CPU module
The WS0-XTDI module cannot be used alone and always requires a main CPU
module.
The simultaneous use of several WS0-XTIO modules is possible, see Section 3.2.
Voltage for the internal logic and the test outputs is supplied from the memory plug via
the backplane bus.
Limited short-circuit recognition!
A WS0-XTDI has two test signal generators. One test signal generator is responsible
for the odd-numbered test outputs X1, X3, X5 and X7, the other for the even-
numbered test outputs X2, X4, X6 and X8.
Short-circuits between test signal generators on module are detected, also between
test signal generators on different modules, provided the test gaps are
≤ 4 ms and the
test periods are ≥ 200ms for the relevant test outputs. Short circuits to 24 V DC (stuck
at high) at inputs connected to test outputs are detected independently of the test gap
time.
Please be aware that at the WS0-XTDI the odd-numbered test outputs X1, X3, X5 and
X7 are connected to one common test signal generator and that the even-numbered
test outputs X2, X4, X6 and X8 are connected to another common test signal
generator. Therefore short circuits between test outputs X1, X3, X5 and X7 cannot be
detected. The same applies respectively for test outputs X2, X4, X6 and X8.
 Take this into consideration during the wiring (e.g. separate routing, sheathed
cables)!
ATTENTION