Siemens S5-135U/155U - Manual (Page 501)

10-5
System Manual
C79000-G8576-C199-06
A control line fault (R/W) occurs if
– the write signal (MEMW/) and the read signal (MEMR/) are active
simultaneously,
– the acknowledgement signal (RDY/) is active without a (MEMW/) or
(MEMR/) signal and
– the address line ’peripheral memory’ (PESP’) has not changed from
status “1” to “0.”
Evaluation of the control signal (PESP’) can be turned off with the S5/7
switch. If the module is used in a programmable controller into which only
I/O modules may be inserted (i.e. no memory modules or CPs), this switch
must always be turned off. In this configuration, only I/O accesses to the bus
are performed and the PESP‘ signal always has the status “1.” It should also
be turned off when using the IM 301, IM 302
1) , IM 304 and IM 308
interface modules for expansion units since a permanent PESP‘ signal can be
applied to them.
If a command output inhibit (BASP) is active, the “BASP” LED is lit.
If one or more faults occur, the corresponding LEDs are lit, the relay contact
commutes and the module no longer acknowledges with the RDY/ signal.
This timeout can be suppressed by opening the S5/8 switch.
10.1.5 Resetting
There are several ways of resetting the module:
– CPKL/ signal = “1” (when the PLC is switched on);
– Trailing edge of the BASP signal (during startup of the PLC or
following return of the load voltage);
– Applying 24 V to the front connector X4 between connections 4
(RESET input) and 6 (L-);
– Linking connections 4 (RESET input) and 5 (L+) with connector X4.
1)
In the S5-115U, the monitoring module cannot be used together with the IM 302 / 311 link.
Control Line
Faults
BASP
Messages
Monitoring Module