Timing Chart - Hitachi SJ Series Safety Function Manual

Chapter 4
4.5 STO state monitor output (EDM)
The STO state monitor output (EDM signal) can be used to
monitor the STO input state and failure state detection in
the safety paths of SJ-P1 using an external device.
■
EDM terminal (ED+ / ED-) and wiring example
I/O terminal
EDM terminal
ED+
Load
Please refer to the signal matrix for the behavior of the STO
state monitor (EDM signal) corresponding to STO state and
internal failure detection state. The EDM signal turns ON
only when both of the STO inputs are given and no internal
failure in the safety paths has been detected.
■Signal matrix
Signal / #1 #2
Item
ST1 *1) OFF ON
*1)
ST2 OFF OFF
Internal No No
Failure
detection
EDM ON OFF
Output to Shut Shut
motor off off
*1) State of contact connected to ST1/ST2 and
corresponding state are as below.
*2) ON or OFF
State of contact Corresponding State
OFF STO
ON Allow operation
Refer to the User's Guide of the SJ-P1 for the detailed
information for wiring on I/O terminal.
See Chapter 11 for the specification of STO terminal
ED-
Wiring
example
#3 #4
OFF ON
ON ON
No No
OFF OFF
Permitted
Shut
off

4.6 Timing chart

The timing chart below shows the state of motor output in
response to STO inputs (ST1/ST2).
■Timing chart
STO1
STO2
Output to
Output allowed
motor
EDM
#5
*2)
*2)
Yes
OFF
Shut
off
4-4
Safety function
OFF (STO)
ON
OFF (STO)
ON
Shut off
OFF
ON
10ms