The DataLink DL3500-DH-485/ Modbus is a gateway that allows Modbus RTU devices to communicate with multiple device's on AB's DH-485 Network.

The DL3500 can be configured as a Modbus network "Master". In this mode it enables SLCs and other devices on a DH-485 network to initiate various commands to read and write coils, inputs and registers of slave devices on a Modbus network. The DataLink Modbus interface can be set for RS232 or RS422/RS485. Communication between Modbus and the DL3500 must be initiated from DH-485 stations as a SLC.

The DL3500 must be the only Master on the Modbus network and does not require a Modbus address. The DL3500 is an active station on DH-485 and requires a unique DH-485 station address number. The DL3500 can accept PLC3 Word Range Read/Write or PLC5 Typed Read/Write DH-485 message commands but always responds with PLC5 message commands. The DL3500 can accept either PLC3 Word Range Read/Write or PLC5 Typed Read/Write commands from any station on DH-485. Typical DH-485 stations that can communicate with Modbus via the DataLink include devices such as PLC3s, PLC5s, SLC5/04s, PCs, HMIs and other intelligent OEM devices.

The Destination Data Table Address is normally used to address a specific File and Word in another PLC on the DH-485 network. This address is interpreted by the DL3500-DH-485 in a specific way and permits data to be mapped from DH-485 station (PLC) and a Modbus slave device. This allows the PLC programmer to directly address a specific register in a Modbus slave device without any previous configuration being necesarry in the DataLink.

Serial Interfacing
CHA - RS232, RS422 and RS485 Interface to DF1 (Full Duplex) device (SLC CH0)
CHB - DH-485 Non Isolated Interface
CHC - Future use