Problem with DF1 half duplex comm's

Can anyone explain how to setup communication with an SLC5/04 using DF1 half duplex, or at least if resetting the processor defaults CH0 to DF1 full duplex.


I originally had the processor setup with CH0 being full duplex, which worked fine when communicating with RSLinx/RSLogix. But trying to get a Citect package to communicate to the SLC, revealed that Citect seemed to only have DF1 half duplex communication driver.
I went into my SLC (using RSLogix) and changed my CH0 comm's to 'half duplex -master'. I haven’t been able to get Citect talking to it, and worse, can't even get into it with RSLinx/RSLogix. Tried setting up (in RSLinx) DF1 Slave Driver with matching config’s to that I had in SLC Ch0, also tried 'DF1 Polling Master' and even 'RS232 DF1 Device' driver with many different config’s (using several docs from AB site) , but to no avail.
Im now thinking of physically resetting the processor by removing the battery. I’ve got the program backed, no prob’s there, but I want to be sure that Ch0 config will default back to DF1 full duplex.

If anyone can give some advice it would be greatly appreciated.

I guess you don't have DH+ connection. Too bad.
Your CPU is now dead. I would buy it from you for $20.
Deal?



Just kidding... Remove battery and everything should
go back to default.

When you are using the Citect driver, you need to set the SLC as 1/2Duplex DF1 SLAVE. Citect will be the master. I have used this setup a number of times quite successfully and through Trio DR900 radios as well.

Odds are good that when you set up the SLC for DF1 Half-Duplex Master you didn't include the right parameters to allow RSLinx as a Half-Duplex Slave to communicate with it. That's a fairly sophisticated setup (you have to configure poll lists, etc).

Just pulling the battery takes too long; you also need to short out the hold-up capacitor. Jumper the Vdd and GND pads on the back side of the main board of the SLC controller for 1 minute and the memory should be drained and it will go back to defaults. See the hardware user manual or the support.rockwellautomation.com website for the position of those pads (about 1.5 inch down and 1 inch in from the upper-right corner) if you're not familiar with them.

paulc20 is of course right on; Citect will be a Half-Duplex Master, and your SLC will be a Half-Duplex Slave.

When you must still use RSLogix 500 through the serial port, you will have to set up RSLinx as a DF1 Half-Duplex Polling Master. Be sure to set up the driver to "allow Msgs to stations that are not on Polling Lists" under the Polling Strategies tab.

Ken Roach said:

That's a fairly sophisticated setup (you have to configure poll lists, etc).

Click to expand...

No offense, Ken, but I have to ask:

What?


and more importantly:

Why?


In general, I try not to mess with the programming port on ANY device. It tends to lead to trouble. But, this seems odd and possibly over-complicated.

By the way, just to beat my own chest a bit: I once used the CH0 port on a SLC 5/04 to transmit ASCII to a Dataliner. In order to prevent collisions when I wanted to go online and program, I used the key switch position to enable the ASCII transfers. If the key switch is in run, the transfers are on. If it's in remote, the tranfers are off. I suppose it's nothing special, but it was still cool to watch (blinkin' lights!).

AK

that's a fairly sophisticated setup (you have to configure poll lists, etc)

Click to expand...

I should be more precise in my language. DF1 Half Duplex Master functionality in a SLC-5/0x controller is more complex than DF1 Full Duplex functionality, and the configuration of the port is correspondingly more complex.

In DF1 Full Duplex, the SLC can only communicate with one device. Usually that device is hooked up with a serial cable, and the DF1 Full Duplex driver in RSLinx has a handy "autoconfig" function to determine the framing, device type, and error checking parameters.

If DF1 Half Duplex, the SLC can communicate with up to 255 devices. There are options for Priority and Normal polling, and the addresses that are polled can be individually specified. Very often the SLC is using a modem for DF1 Half Duplex communications, so the handshaking and timing settings of the modem must be considered as well.

If you didn't know your way around the DF1 HD Master driver configuration, you'd probably fail to configure the poll list the first time, and the default message method is to use MSG-initiated communications, not the Polled communications you'd need for the SLC to talk to an RSLinx DF1 HD Slave terminal.

That's why when lalion posted that he'd essentially "accidentally" configured the SLC for HD Master, I thought it best to scratch the configuration and start over again.

Good work, by the way, conditioning your ASCII logic with the keyswitch. I've often wished for the SLC to have a runtime softswitch between User and System modes, or to enhance the DF1 Polling Master poll list to be modifiable at runtime the way it is in the PLC-5.

Ken Roach said:

If DF1 Half Duplex, the SLC can communicate with up to 255 devices.

...you'd probably fail to configure the poll list the first time...

Click to expand...

That sounds a lot like setting up devices on DeviceNet or ControlNet. If you set up the polling list, do you need to write program code to read data out of a remote?

I've never used this feature on the SLC, and I'm rather curious how it works and what it's intended for.

AK