How to split the DF1 Port of SLC500, MicroLogix, CompactLogix, PLC5, ControlLogix or any Allen Bradley DF1 Port Device.











In case you have the serial DF1 port of an Allen Bradley PLC, like PLC5, SLC 5/05 1747-L551, SLC 5/03 1747-L533, CompactLogix 1768, CompactLogix 1769, Control Logix 5563, MicroLogix 1400 (1766 MicroLogix ), MicroLogix 1200 (1762 MicroLogix ), MicroLogix 1100 ( 1763 MicroLogix ), MicroLogix 1000 ( 1761 MicroLogix ), or any DF1 device where the DF1 port is already being used and you want to connect another DF1 device to it, usually you would get the Allen Bradley 1747-DPS1 DF1 port splitter but that is being discontinued by Allen Bradley and now your best solution out there is Equustek’s DL4000-DFX  which allows three DF1 serial devices to simultaneously communicate with each other, below is the link to DL4000 page .

The DL4000 can be programmed with other firmware versions to perform other protocol conversions, such as; 

DL4000-DMX allows DF1 to communicate with MODBUS  and can be configured for MODBUS master or MODBUS slave, it also can be configured to connect via RS232, RS422 or RS485.

DL4000-MMX interfaces MODBUS  RTU to MODBUS ASCII (Allows Modbus RTU devices to communicate with multiple Modbus ASCII devices), also can be configured to do RS232, RS422 or RS485.

DL4000-DAS Interfaces serial ASCII devices (Scanners/Printers) to AB DF1 protocol.

DL4000-MAS Interfaces ASCII device to MODBUS RTU Slave.

DL4000-PM Provides a DF1 Half Duplex Master Interface to Allen Bradley Power Monitor 3000 then sends the converted data via Modbus to specified Slave RTU devices.

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.


MicroLogix 1400 MODBUS TCP/IP to DH+ 1785 PLC-5 or 1747 SLC 5/04

image1If you are in a situation where you have an Allen Bradley MicroLogix 1400 with MODBUS TCP/IP support, and you want it to communicate with the DH+ network devices like Allen  Bradley’s PLC5 and SLC5/04, where the MicroLogix Ethernet port is configured for MODBUS TCP/IP Master so that it can get data from any DH+ Device ( PLC5s and SLC504s), or the other way when the DH+ Nodes or devices like PLC5 or SLC5/04 wants to get data from MicroLogix which it’s Ethernet port is configured in this case for MODBUS TCP/IP Slave, that said not many easy affordable solutions are out there, however Equustek Solutions DL6000-MEDH+ can do it easily, when it is configured as a Slave where the MicroLogix is Ethernet port is configured as a Master.

Here the DL6000-MEDH+ will allow the MicroLogix to communicate with all PLC5s and SLC504s or any Allen Bradley DH+ node connected to the same Data Highway Plus network which the DH+ port of DL6000-MEDH+ is connected to, that is accomplished when the MicroLogix MODBUS connects to the IP address of the DL6000-MEDH+ then by using the DH+ nodes address numbers as MODBUS Slave IDs to address the PLCs and SLC504s.

Also when the DH+ PLC5s or SLC 5/04s are initiating communications and are requesting data from the MicroLogix then the DL6000-MEDH+ Ethernet side will be configured as a Master while the MicroLogix Ethernet port will be configured as a MODBUS TCP/IP Slave.

Here the DL6000-MEDH+ will allow any DH+ device to request data from the MicroLogix.

More details about the DL6000-MEDH+ can be found from the link below.

DL6000-MEDH+ as A Master Application Note link below

DL6000-MEDH+ as A Salve Application Note link below