Earth connection, Micro400 light curtain, Start mode – Rockwell Automation 440R MSR42 Control Module User Manual User Manual
Page 8: Manual start, Automatic start, Minimum off time, Edm or start release, Original instructions
 
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Light Curtain Multi-Function Control Module User Manual
Original instructions
Earth connection
The earth of each MSR42 control module is realized through the 
connection to the mounting rail. Consequently it is important to ensure, 
that the mounting rail has a good earth connection.
Micro400 light curtain
The two RJ45 sockets on the lower portion of the control module are for 
the connection of Allen-Bradley GuardShield Micro400 (white = E = 
emitter; blue = R = receiver). To help protect the RJ45 connectors the 
cables have to be snapped into the provided cable holders at the.MSR42 
housing.
Start mode
The MSR42 can be configured to have the following start modes:
• automatic start or
• manual start.
In case of the basic configuration the start mode can also be configured 
without the configuration software. By connecting +24V to GPI03 and 
GPI04, automatic reset is enabled (see wiring diagrams).
Manual start
When all of the inputs of the safety system have a safe signal, depressing 
the start button will cause the two safety OSSD outputs to change from 
low to high. If a MSR45E relay expander module is connected, it will 
close. If more than one safety component is configured, then all 
components must have safe signals to all inputs before a start is allowed. 
The start button is monitored to prevent an unintentional start. Pulse 
length must be between: 50 ms and 5 sec. If the start impulse is longer or 
shorter, the start input will be ignored by the device. The configuration 
control document identifies which terminal the start button is connected 
to. If the start button is connected to IN1or IN2 then a red LED 
indicates that a start signal is present, a green LED indicates no signal is 
present.
Table 4
Warning: Important safety advice:
Automatic start
If a safety component is configured for “automatic start”, then, after the 
activation and the deactivation of the safety component, the two OSSD 
outputs will change automatically from low to high again and if 
connected the MSR45E expander relay contacts will automatically re-
close.
Minimum off time
According to the standard IEC 61496-2 a safety light curtain must have a 
minimum safety output off time of 80 ms. This means that even in the 
case of a very short safety light curtain interruption, the safety outputs 
will stay low (Relays = open) for 80ms at minimum. A start signal will 
only be recognized after the 80ms duration.
EDM or start release
If an MSR42 is used with external relays or contactors, the contacts of 
that device must be monitored. An example category 4 application has 
two external contactors, each with force guided contacts must be 
inserted. For monitoring the function of these contactors, each relay 
block must have at least one normally closed contact which is fed back in 
series to IN2 (or IN1 depending on configuration) of the MSR42 
control module (e.g. Figure 4).
Two options are possible for this monitoring:
1. Start release: The signal at the corresponding input terminal must be 
high before the start button is pressed (this means: the normally closed 
contacts of the external relays must be closed before allowing a start). The 
option “start release” is pre-configured in the MSR42 control module 
(440R-P226AGS-NNR) (e.g. Figure 4).
2. EDM (external device monitoring): The input signal of the EDM 
terminal is always monitored. This means: not only at the beginning 
before a start the signal must be correct. Also after the start a signal 
change must happen, otherwise an emergency stop occurs. If a high signal 
is present for longer than 5 seconds, a lock-out will occur. 
If the configuration control document shows that EDM or start release 
must be attached to terminal IN 1 or IN 2, then the meaning of the 
respective LED is shown below.
Table 5
The start release or EDM input is not cross-fault monitored and 
therefore not a safety input.
Terminal
LED green
LED red
IN 1 or IN 2
No start signal present
Start signal present (button pressed)
It is fundamental that the start button be 
mounted so that the danger area is clearly 
visible. That is, when pressing the start 
button it must be guaranteed that no one 
is detained within the danger area.
According to EN 60204 article 9.2.4.4.2 a 
system may not automatically restart, 
even after the cause of the shutdown has 
been eliminated and thereby another 
danger may still exist to the operator. If 
the MSR42 control module is configured 
with an “automatic start”, this 
requirement must be fulfilled by further 
measures.
Terminal
LED green
LED red
EDM at IN 1 or IN 2
EDM signal okay
EDM signal wrong
Start release at IN 1 or
IN 2
Start release signal okay
Start release signal wrong