6
Operating instructions
Safety switch with interlocking function
MZM 120
EN
Table 2: flash codes red LED
Flash codes
(red)
Designation
Autonomous
switch-off after
Error cause
1 flash pulse
Error (warning)
at output Y1
30 min
Fault in output test or voltage at output Y1, although the output is
disabled.
2 flash pulses
Error (warning)
at output Y2
30 min
Fault in output test or voltage at output Y2, although the output is
disabled.
3 flash pulses
Error (warning)
cross-wire short
30 min
Cross-wire short between the output cables or fault at both outputs.
After 30 minutes, voltage switch-off/on required
5 flash pulses
Actuator fault
0 min
incorrect or defective actuator
6 flash pulses
Latching force fault
0 min
Latching force has dropped below 300 N (e.g. actuator misalignment)
10 flash pulses
Magnet temperature too high
0 min
The magnet is too hot: T > 70 °C.
continuous red signal internal error
0 min
6.3 Safety switch with serial diagnostic function
Safety switches with serial diagnostic cable have a serial input and
output cable instead of the conventional diagnostic output.
Max. 31 safety switchgear with serial diagnostics can be wired in series.
For the evaluation of the serial diagnostics line either the PROFIBUS-
Gateway SD-I-DP-V0-2 or the Universal-Gateway SD-I-U-… are used.
This SD-Gateway is integrated as slave in an existing field bus system.
In this way, the diagnostic signals can be evaluated by means of a PLC.
The necessary integration for the integration of the SD-Gateway is
available for download at www.schmersal.net.
The response data and the diagnostic data are automatically and
permanently written in an input byte of the PLC for each safety switch
in the series-wired chain. The request data for each safety switch are
transmitted to the component through an output byte of the PLC.
In case of a communication error between the field bus gateway and
the safety switch, the switching condition of the interlocking device is
maintained.
Error
A fault has occured, which causes the safety outputs to be disabled.
The fault is reset, when the cause is eliminated and bit 7 of the request
byte changes from 1 to 0 or the safety guard is opened. Faults at the
safety outputs are only deleted upon the next release, as the fault recti-
fication cannot be detected sooner.
If more than one fault is detected at the safety outputs, the
component will be electronically locked and a normal fault
reset will no longer be possible.
To reset this type of interlocking, the component must be
isolated from the power supply after elimination of the error
causes.
Error warning
A fault has occured, which causes the safety outputs to be disabled
after 30 minutes. The safety outputs initially remain enabled.
Diagnostic error (warning)
If an error (warning) is signalled in the response byte, detailed fault
information can be read out.
Detailed information about the use of the serial diagnostics
can be found in the operating instructions of the PROFIBUS-
Gateway SD-I-DP-V0-2 and the Universal-Gateway
SD-I-U-….
Accessories for the series-wiring
To provide for a comfortable wiring and series-wiring of SD compo-
nents, the connectors and the SD-2V-F-SK SD junction boxes (variant
for the field in closed enclosure) and SD-2V-S-SK (variant for DIN rail
mounting in the control cabinet) are available as accessory.
Table 3: I/O data and diagnostic data
Bit n°
Request byte
Response byte
Diagnostic error warning
Diagnostic error
Bit 0:
Magnet in,
error reset
Safety output activated
Error output Y1
Error output Y1
Bit 1:
Latching force bit Actuator detected
Error output Y2
Error output Y2
Bit 2:
Latching force bit Solenoid interlock locked
Cross-wire short
Cross-wire short
Bit 3:
Latching force bit ---
Magnet temperature too high
Magnet temperature too high
Bit 4:
---
Input condition X1 and X2
Locking blocked or F < 300 N
incorrect or defective actuator
Bit 5:
---
---
Internal device error
Internal device error
Bit 6:
---
Error warning
Communication error between the field bus
Gateway and the solenoid interlock
---
Bit 7:
Error reset
Error (enabling path switched off)
Operating voltage too low
Operating voltage too low
The described condition is reached, when Bit = 1
