Equustek’s DL3500-DF1/DH+, a direct replacement for Allen Bradley’s 1770-KF2 or 1785-KE, DF1 to Data Highway Plus (DH+) Interface

image1Many Allen Bradley PLCs, like MicroLogix 1400 (1766 MicroLogix ), MicroLogix 1200 (1762 MicroLogix ), MicroLogix 1100 ( 1763 MicroLogix ), MicroLogix 1000 ( 1761 MicroLogix ), CompactLogix 1768, CompactLogix 1769, SLC 5/05 1747-L551, SLC 5/03 1747-L533, and other manufacturers Distributed Control Systems (DCS), like the Honeywell DCS (TDC 3000) or the Emerson DeltaV DCS with PSIC (Programmable Serial  Interface Card) that have a serial RS232 DF1 port, most of the time they need to communicate with an Allen Bradley Data Highway Plus (DH+) device like the PLC-5, SLC 5/04, ControlLogix 1756-DHRIO, a Panel View, or any other DH+ device. The solution for that used to be using one of Allen Bradley’s 1770-KF2 or the 1785-KE to interface between the DF1 and DH+ by connecting the DF1 side to the RS232 DF1 port, while the other side (DH+) would be daisy chained to the Data Highway Plus Network, but Allen Bradley phased out the 1785-KE and 1770-KF2, both now are obsolete. So what options are out there for the plant to continue working until they are ready for an upgrade to Industrial Ethernet IP?

The Equustek DL3500-DF1/DH+ is a direct replacement for the Allen Bradley 1770-KF2 and the 1785-KE, in all those cases previously mentioned, the DL3500 will be transparent where any of the above mentioned PLCs or DCS will look like any other DH+ device or PLC node on the Data Highway Plus Network allowing communications between all of them.

An application note showing how to setup and configure the DL3500 DF1 to DH+ allowing a MicroLogix 1000, SLC 5/05 1747-L551 and a SLC 5/03 1747-L533 and make them communicate like any other DH+ PLC on the Data Highway Plus Network ( DH+ ) then using RSLINX and RSLOGIX 500 to go online with them, are available from this link.


In any case, when you have the discontinued Allen Bradley legacy 1770-KF2 or the 1785-KE damaged by lightning or any other failure and needs to be replaced, your best solution is the Equustek DL3500-DF1/DH+, as it is a direct replacement for the AB 1770-KF2 and AB 1785-KE.

Similar to Allen Bradley’s 1770-KF2, 1785-KE and 1784U2DHP, the DL3500-DF1/DH+ will allow your PC HMI SCADA running with any RS232 DF1 driver or RSLINX 1784U2DHP driver to communicate with and go online with all DH+ nodes (PLC-5s & SLC 5/04s) that are connected to the Data Highway Plus network where the DL3500 DH+ port is connected to as well.

The DL3500 DF1 side has many physical options to connect serially though RS232, RS422, RS485 & USB with baud rate setting configurable range from 4800 to 115200 baud and the DH+ with baud rates of 57.6KB, 115.2KB and 230KB, the DL3500 can be powered from the USB or an external DC 9-27V.

More details and other application notes on Equustek DL3500 can be found from this link.