Judging Input Errors - YASKAWA MP210 Series User Manual

(2) When Checking the Operation Status of a Slave Device with the Application at the
Master Device
Checks that the data has been
refreshed. If it has not been
refreshed correctly, there is
judged to be an operation error
at the slave device.
• Processing at master device
The application at the master device checks that the scan counter value has increased by 1 compared to the
previous value. Since the scan counter is 1-byte data, it is only the least significant byte that is checked.
If the data has not been refreshed correctly, it is judged that there is a problem with operation at the slave
device.
• Processing at slave device
The application at the slave device increments the setting for the first word of the output registers allocated to
the Built-in SVB Module of the MP2100M by 1.
Note: In the example above it is assumed that the same setting has been made for the high-speed scan cycle
at the master device and the high-speed scan cycle at the slave device.
If the two scan cycles are different, they have to be refreshed and checked accordingly.
F.3.5 Judging Input Errors
(1) Procedure for Judging Input Errors in an Application Program
When an input error is judged to have occurred, execute error processing such as discarding the read input data.
(a) For the Master Device
1. Check the S register "I/O error status".
In the I/O error status of the slot where the SVB Module is installed, check whether the bit for the station
allocated to the MP2100M is ON. The ON status indicates that an input error has occurred.
When an input error has occurred, the input data is cleared to 0.
2. Check the "Slave status".
Check that the second word, "Slave status", from the first address of the input registers allocated to the
MP2100M has assumed the status indicated below.
bit 1 WARNG = OFF
bit 2 CMDRDY = ON
bit 7 SYNC = ON (only when the slave CPU synchronization mode is enabled)
If the status is other than that indicated above, the probable cause is a command issued from the master
device or an operation error at the slave device.
3. Check the scan counter.
Check that the first word, "Scan counter" of the input registers allocated to the MP2100M is refreshed
correctly by the application in accordance with the fixed rules.
If it has not been refreshed correctly, the probable cause is an operation error at a slave device.
Master device
Input registers
Scan
IW
counter
IW +1
↓
↓
Slave device
Output registers
Scan
OW
counter
OW +1
F.3 Operation
Refreshed by the
application every
scan
F
F-19