Mitsubishi Electric MELSEC Q Series Programming Manual page 64

2 SAFETY OBSERVATION FUNCTION
Error location
Restorable error
Controller
Non-restorable error
Restorable error
Servo amplifier
Non-restorable error
Network
[Restrictions]
The communication cycle of safety communication is set by parameter. When the
processing time of safety communication exceeds the set communication cycle, a
safety observation error occurs, and safety observation function is not executed.
Review the PLC CPU processes and shorten the scan time, or change the
communication cycle to a larger value.
When an error related to safety observation function occurs when safety
communication function is enabled, the following operations occur depending on the
location of the error and the error type.
Error type Shut-off signal
(Note-1)
(Note-2)
OFF
(Note-1)
(Note-2)
—
(Note-1): Error due to an external factor (speed monitoring error, safety signal comparison error etc.)
(Note-2): Error due to an internal factor (memory error etc.)
(Note-3): The transition to STO is executed by the user safety sequence program.
(The user safety sequence program does not stop.)
(Note-4): Communication with SSCNET /H is maintained.
(1) When operation cycle is 0.22ms, a safety observation error occurs, and safety
observation function cannot be used.
(2) There is a restriction on the number of servo amplifier axes per line for
SSCNET /H communication where safety communication can be used,
depending on the connection configuration of the servo amplifiers and
SSCNET /H head module.
The number of axes per line for SSCNET /H communication where safety
communication can be used is shown below.
Table 2.1 Number of servo amplifier axes where safety
communication can be used
Number of SSCNET /H
head module stations
4
3
2
1
0
(Note-1): When the number of connected axes per SSCNET /H communication line for is 12 or less,
safety communication is possible for all axes, regardless of the number of head module
stations.
The servo amplifiers to use safety communication are set by parameter. When
the number of servo amplifier axes to use safety communication set in the
parameter exceeds the above restrictions, a safety observation error occurs, and
safety communication cannot be used.
Safety communication
Communication with all axes
maintained
(Note-4)
All axes disconnected
(Note-4)
Error axis disconnected
Communication with other axes
maintained
Number of connected axes per SSCNET /H communication line
16 15
7
9 10
11 12
13 14
15 15
2 - 27
Status of servo amplifier
(Note-3)
STO by user program
All axes in STO
Error axis in STO
Other axes in STO by user program
(Note-3)
14
8 10
12
14
(Note-1)
13
11
13