The 1756-L61A protocol converter is a bridge, or industrial gateway, which is used at the link layer for storing and forwarding packets between LANs or between LANs and WANs as well as for switching between different physical interfaces. If the Ethernet networks are of different types (e.g. Ethernet as well as Token Ring), it is not possible to connect the two networks by means of data link layer protocols alone, since they do not recognise each other’s frame format transmission method.

The 1756-L61A has two gateways for the different network types, which are connected to each other by means of a gateway and therefore act as a protocol converter. You can choose Profibus-DP Serial Gateway series products, through the supporting software can choose different types of serial ports (RS232/422/485/) Anybus Communicator provides a Modbus RTU master mode.

1756-L61A In this mode the gateway polls one or more Modbus slave devices and maps the data retrieved from the devices to the gateway’s internal storage. The user can choose to use predefined standard Modbus commands, or use the gateway’s advanced data processing capabilities to define communication messages so that only the selected data is exchanged between the gateway and the fieldbus master. This functionality is well suited to using the temperature inspector as a slave and then utilising the gateway to read the data it collects in turn.