We are using an Anybus gateway (AB7007) to interface Ethernet IP network to a RS485 based proprietary protocol. The AB7007 is configured for Produce/Query transactions. The configuration file is attached.
For the first transaction the Update mode is set for ‘On data change’.
My queries are
- Is it possible for a scenario where the host PLC (Rockwell PLC) updates the Anybus register slowly, or is this always a fast process ??
If the update is slow then will multiple transactions be created on the sub-network??
For example: The host PLC sets a value of 520, as update is slow, the Anybus gateway will first show some value 0x08 (address 203, ), now sub-network command will be generated as data change on 203 was detected. The PLC will then write the last byte 0x02 at address 202, another sub-network command is generated, as data change on 202 was detected.
To avoid this problem, I could use trigger bytes instead of ‘data change’, however I want to know if the above scenario is possible.