Does 1761-L16AWA supports half-duplex serial communication?

[manojvivek]

Hi,

I am new to Micrologix1000. I am using 1761-L16AWA. Does this PLC support half-duplex communication through serial link (using DF1 protocol)? I am using only one PLC and so not planning to use modems.
Will such a set up work?

Thanks in advance for any help in this regard.

regards,
Manoj

 

[RoTaTech]

in Logix, the standard Micro1000 only uses DF1, but there is a Micro1000 DH485/HDSlave version. I don't know the catalog number, though...

 

[Ken Roach]

It's the same part number, just a different Series letter. Series D and later MicroLogix 1000 discrete controllers do support DF1 Half Duplex protocol.

 

[manojvivek]

It is Series E FRN 1:10

Hi,

The PLC I am using is MicroLogix1000 1761-L16AWA of Series E FRN 1.10. I have also learned from AB's site that "Series D and later MicroLogix 1000 discrete controllers do support DF1 Half Duplex protocol". But when I am trying to communicate to it by configuring RSLinx to DF1 Half duplex, the PLC is not detected. There seems to be some problem. Any idea?

rgds,

Manoj

 

[Ken Roach]

DF1 Half Duplex allows hardware handshaking and adjustable RTS/CTS timing, as well as full control of baud rate, data framing, and error checking.

The bad news is that if only one of those settings doesn't match between your MicroLogix and your communication driver, you won't be able to connect to the controller.

DF1 Full Duplex users who use the "Autoconfigure" button are spoiled in that regard !

If you took good notes about what your DF1 Half Duplex settings were when you downloaded the program, configure the "DF1 Half Duplex Polling Master" driver with matching port and protocol settings. Don't forget to put the node number of the MicroLogix in the Poll List.

I've never had any luck just with changing the regular DF1 driver's mode from Full to Half duplex.

In the worst case, you can plug this controller into an operating DH485 network and it will Autoswitch to that protocol so you can communicate with it again.