How it works?

Arrow basic modbus process creates a simulated modbus network by starting virtual devices on Postman side. Every PLC would have its shadow copy on unrestricted network, allowing data stored in the actual PLC device to be accessible by business or reporting tools while keeping it safe from tampering.

Arrow Guardian is responsible with reading data from individual modbus slaves, encapsulate into a transferrable format and send it to Postman from the fiber interconnection. Last information is stored in Postman memory for a period of refresh time interval defined in Guardian IOT settings menu. Neither Guardian nor Postman writes the retrieved information into a permanent datastore, preventing any data leak. Data requester ask register informations from Postman using standart Modbus protocol. If Guardian stops sending information for one modbus slave, Postman also stops providing this information and return relevant error codes.

In case a virtual PLC device is removed from rule sets defined in Guardian “Data Collect” menu, this virtual device will be removed from Postman and unaccessible error code would return if any receiver tries to ask information from this virtual device.

You can create up to 20 virtual devices per pair. This number will be increased in following versions.