YASKAWA SGD7S-1R9D Product Manual page 447

14.4 Sync Manager Communications Objects
In this example, a failure in receiving the process data occurs every other DC (Sync0) cycle.
After eight DC cycles, the internal error count reaches the Sync Error Count Limit, and an error
occurs.
No alarm will be detected if the DC mode is disabled or when the Sync Error Count Limit is set
to 0.
Important
14-16
1. Set a suitable cycle time for updating the process data according to the requirements of the
application.
2. Determine if the default setting of the Sync Error Counter Limit is suitable for the requirements
of the application. With the default value of 9, network frames will be lost (SM2 reception
events will not occur) three times consecutively before an alarm occurs in the SERVOPACK.
If the setting of the Sync Error Counter Limit is too small, alarms will occur even when there is
no problem in the application.
3. Noise may cause communications errors in the SERVOPACK. Check the SERVOPACK wiring
and make sure that it has been performed to minimize the influence of noise. Implement noise
countermeasures if necessary. Refer to the following section for information on noise
countermeasures.
4.1.2 Countermeasures against Noise on page 4-5