DL06 Bricked?

[Coolerman]

I am new here and to PLC's in general. I have two Koyo DL06s: One that is new out of the box yesterday, and one about two years old that I have apparently managed to brick with some code I put in it.
I thought the first one had simply failed, but when I put the new code on the second one it also failed with the exact same symptoms. What follows is the whole story with as much detail as I can give you.

Each DL06 has a HO-ECOM100 in slot 4 and a LCD display installed. I am using Directsoft 5.3 The code is attached as a zip file. Here is what happened to the first one:

I was attempting to build a "string" in Vmem that contained the init characters, message, and termination characters to send to a remote LED sign connected to Port 2. I had it working (at least I had blinking TXD lights on port 2) but the sign was not responding. I realized that I had the baud rate on port two set wrong so while the program was running I opened up the secondary port setup through DirectSoft and changed the baud rate from 19200,8,n,1, to 9600,8,n,1. I noticed that the last field which normally contains the Vmem address of where to store the comm port parameters had TA0 instead of the V2000 it normally has. I changed it to V2000 and clicked the "Write to PLC" Icon. It immediately froze for several seconds then started saying there was a Transport Protocol Timeout. NOTHING I did would let me talk to it again. At one point the CPU light was on solid red and the LCD display would not respond to any button presses. A reset of power got the CPU light not red and the display started responding again. However, still no comms. I ran Netedit3 and was able to see the HO-ECOM100 but when I ran the CPU test it failed. A quick call to tech support and was told if the red CPU light is on the CPU is toast.

So I ordered a replacement PLC. Got it yesterday, installed the old ECOM card and LCD display, tested comms which were fine, loaded a small program which ran fine, then loaded the sign program and told it to run. It ran but I was not getting a blinking TXD light. Duh! I had forgotten to setup the secondary com port. So again left the program running, opened the port setup, put in the exact same parameters as before and clicked the "Write to PLC" icon with the exact same results! It froze then started with the Transport Protocol Errors , red CPU light and the LCD display became unresponsive.
Is it really possible to brick a DL06? Is there anyway to "factory reset it" to get the bad code out of memory when you can't talk to it? (Also I tried talking to it through Serial Port one but it will not talk at all)

Help...

 

[nwminnesota_plctech]

I have had a lot of little issues with automation directs DL series PLC's I will look at your code but it might be a few days.

 

[Coolerman]

Well, first off, I guess you really can't brick a DL06 with software!
I figured out how to bring it back "alive". You old timers can get a good laugh at this, but the one thing I had not tried was to apply power to the PLC while the Run/Stop switch was in stop position. One would think that simply stopping the program using that switch would allow it to function again, but whatever that code was doing would not let that happen. Once i figured that out I was able to get both the PLC's to function correctly. Now I just need to figure out exactly what that code was doing to the PLC to cause the CPU light to be red and to fail the CPU test.

nwminnesota_plctech
My company has been using the DL06 PLC for several years as a simple output control for a asphalt load out system. Our PC talks to the PLC over Ethernet using ModBus and does most of the load out control with the PLC being used mostly for safety stuff like E-Stop management and timing control. This is the first time I have tried doing anything through the com ports. I am sure it's something simple and will be looking at it today.

If you wouldn't mind sharing some of the things you have experienced with the DL06 it might save me from going down the same path.

 

[icky812]

There really isn't anything in this code that should keep the PLC from communicating.

As for your code there is nothing technically wrong other than using some timer addresses in rung #1.

TAx is for the timer accumulator and is reserved for internal timers. IE this is where the timer stores it's accumulated time at.

The SP4 bit is a 50% duty cycle bit. So rungs 11 and 12 are firing continuously for 500 milliseconds and off for 500 milliseconds. You probably meant for this to be a one shot. Take SP4 to a C20 PD coil and use this in place of SP4 in rung 11 and 12.

You should condition rung 12 with the PRINTV busy bit, a normally closed C11.

 

[keithkyll]

Sounds like you have a bad setup for the com ports. After you download, the com ports get reconfigured from default, and you loose coms right after the first download.

 

[just the cowboy]

Clear scrath pad

After a clear memory do an intialize scratch pad and see if that helps.

 

[nwminnesota_plctech]

I used a DL205 setup after a while my input modules would not work from the UPS when power would flicker off and on but would still work with the power company power. What I was using seemed to be more programming than other PLC's It is a cheeper PLC but the programming seemed to be more so buying a cheep PLC didn't really save me money

 

[Coolerman]

Well... icky812 was on the money with the timer accumulator issue. Don't know why the LD command comes up with TA0 as the default but I was the one that did not notice that! The VALUES I put in were correct but of course they were being used as timer values not the K values I intended.

Once I got that corrected it worked almost perfectly. Just as a note I was using the SP4 one second contacts to slow it down for trouble shooting as this was a stand alone program while I learned how to talk to the sign. When I put it into the actual program those will be replaced with the actual contacts that trigger the messages to the sign.

Thanks all who posted. This place is great... I will lurk here, more than post as I am still learning. but it's good to know I can ask dumb questions and not get flac for it.