YASKAWA SVC - Effect on Application Program

6.6 Slave CPU Synchronization
6.6.9 Effect on Application Program
6-28
2.
Check the Command Status input register (second word from the start).
Bit 0 D_ALM = 0
Bit 1 D_WAR = 0
Bit 2 CMDRDY = 1
Bit 7 SYNC = 1 (Only when slave CPU is synchronized.)
Bits 8 to 11 CMD_ALM = 0
Bits 12 to 15 COMM_ALM = 0
If any bit status is shown other than the above status, there is an error in the slave. Refer to the fol-
lowing section for specific errors.
11.3.7 Command Status on page 11-33
Recovering from Input Errors
Even if an input error occurs, processing in the MP3000 will automatically switch to normal
reception, so no specific operation is required for recovery. However, if input errors occur fre-
quently, check the following items.
• Is the same station address set for more than one station?
• Has the count reached the value set in SW00044 (H Scan Exceeded Count)?
Note: If the count has reached the set value, set a longer scan time.
• Is there a problem with the MECHATROLINK cable (e.g., is it broken or disconnected)?
6.6.9 Effect on Application Program
This section describes the effect of the system on the application when the communications
cycles between the master and slave change from asynchronous status to slave CPU synchro-
nized status. The setting to restart slave CPU synchronization is also described. Refer to the
following section for countermeasures of the system’s effect on the application.
Precautions (page 6-30)
Overview
The slave CPU synchronization function synchronizes the slave cycle with the master cycle.
When the status is changing from asynchronous status to slave CPU synchronized status, the
processing that is performed by the system at the slave may affect the application at the slave
as described in the following table.
For the slave MP3000 to detect an error, the input from the master MP3000 must be completed
normally at least once. For example, if the power supply to the slave MP3000 is turned ON when
it is not connected to the master, the bit for the local station in the I/O Error Status will remain at
0 (no error).
Important
System Processing at Slave Effect on Application
Adjustment of the start of the high-
speed scan cycle
• The high-speed scan cycle may temporarily be disturbed.
• Shock may occur for an axis being controlled by the SVA-01.
• An axis being control by the SVB-01 or SVC-01 may suddenly
stop.
• The counter values for LIO-01, LIO-02, LIO-06, and CNTR-01
may be disturbed.
Resetting MECHATROLINK communica-
tions
(SVC, SVC32, SVC-01, and SVB-01)
• Position information may be lost.
• Zero point return information may be lost.
• The software limits may be disabled.
• Controlled axes may stop suddenly.