SCAN Function Block
|
The Scan (SCAN) function block allows stand-alone peer-to-peer communication among devices on a RS485 network. Normally the peer-to-peer communications (RAV/RDV blocks) would be supported by a MBus_ioFlash network controller master device. However, in the absence of such a device, one of the devices can be made to serve as the master network scanner instead. Adding a SCAN block to one of the device's program page automatically makes that device a master controller. When activated it will scan the necessary devices on the RS485 network so that the peer-to-peer communications can occur.
** Important note: on an RS485 network there can only be one master device, otherwise communications from one master would collide with the other. Therefore you must make sure that the SCAN block is deactivated before attempting remote communications from MBus_ioFlash or any other master type communication device.
Parameter | Description |
Name | Function block name, see common parameters |
Input | Input value to control whether the SCAN block is active or not. See note above. |
/ | Mixed inputs option, see common parameters |