I am running m90/91 unitronic plc in 4 thermoforming machines. Up til now I have never had a problem accessing the controller with my laptop. Today I am unable to access any of the controllers! I am getting the following error. Unable to open com1. It says to check communication settings and check wire and to reboot. This has now happened on 2 seperate computers. I can't get in to dump program and I am stuck as I now need to get a new machine up and running. Help Please.
com port trouble
- Thread starter jlicker
- Start date
Just to eliminate the obvious, are you running any other programs or TSRs that require the comm port?
Assuming that you are running Windows,
Check your comm status by going to the command prompt and type "Mode Com1:" <enter>
This won't cure the problem, but it will tell you if your comm port is available.
Assuming that you are running Windows,
Check your comm status by going to the command prompt and type "Mode Com1:" <enter>
This won't cure the problem, but it will tell you if your comm port is available.
jlicker said:
Looks like you have a problem with your computer comm port. Was there any new software installed on your computer that will automatically use your comm port? I know that if you use RSLinx and have a RS-232 driver that starts up automatically, then it will prevent you from using that comm port until you turn off that dirver in Linx.
Hope this helps and good luck,
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I am having the problem using 2 different computers. I did disbla my modem in my laptop and that still did not work. I am almost convinced it is somthing in the ladder program that I had written for me. I am running windows xp pro on pc and home on laptop. Nothing substantial has been installed as far as i can remember.
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MartB
Lifetime Supporting Member
If you can't see your com port at the command prompt than you can be pretty sure that whatever software you are using can't see it either.
It sounds like you have a TSR or some other software that has taken possesion of your com port or you have a hardware issue.
It sounds like you have a TSR or some other software that has taken possesion of your com port or you have a hardware issue.
rsdoran
Lifetime Supporting Member
For XP go to Start then Run and type in cmd
This will open a command line window, then type in mode com1
see what it offers then.
Another method is get in to Device Manager, couple ways to do this, go to control panel, with it in classic view double click on System, then once click Hardware, then click Device Manager. Look in ports for appropriate com port then click it to get its properies.
You can look in Task Manager (ctrl, alt, del) and see what applications or processes may be running that could interfere.
I would also check Startup and msconfig to see what is being started on power up.
This will open a command line window, then type in mode com1
see what it offers then.
Another method is get in to Device Manager, couple ways to do this, go to control panel, with it in classic view double click on System, then once click Hardware, then click Device Manager. Look in ports for appropriate com port then click it to get its properies.
You can look in Task Manager (ctrl, alt, del) and see what applications or processes may be running that could interfere.
I would also check Startup and msconfig to see what is being started on power up.
I was able to read the com1 line now. It reads the following
baud 9600
parity 1
data bits 8
stop bits 1
time out on
xon\xoff off
cts handshaking off
dsr sensitivity off
dtr circuit on
rts circuit on
Is there anything you spot that could be a problem.
When I went into my desktop it stated that com1 is currently available, I have disabled my modem in my laptop just in case it was causing a conflict, but I have not touched anything in my desktop. Any help would be greatly apprciated
baud 9600
parity 1
data bits 8
stop bits 1
time out on
xon\xoff off
cts handshaking off
dsr sensitivity off
dtr circuit on
rts circuit on
Is there anything you spot that could be a problem.
When I went into my desktop it stated that com1 is currently available, I have disabled my modem in my laptop just in case it was causing a conflict, but I have not touched anything in my desktop. Any help would be greatly apprciated
ndzied1
Lifetime Supporting Member
One way to verify if a serial port is working is to connect it to somethign else (other than the device you are having a problem with) and see if you can make it work.
The easiest way to do this is is to plug a USB to serial adapter into a usb port on your computer. Then connect it to the hard serial port on your computer with a cross over cable (sometimes called a null modem cable).
Then open up two instance of hyperterminal (Start/Programs/Accessories/Communications) and connect one to the com port of the usb adapter and the other to the com port of the hard serial port. Type in one screen and it should show up in the other.
Of course, this assumes you have a USB to serial adapter and know how to use it
The easiest way to do this is is to plug a USB to serial adapter into a usb port on your computer. Then connect it to the hard serial port on your computer with a cross over cable (sometimes called a null modem cable).
Then open up two instance of hyperterminal (Start/Programs/Accessories/Communications) and connect one to the com port of the usb adapter and the other to the com port of the hard serial port. Type in one screen and it should show up in the other.
Of course, this assumes you have a USB to serial adapter and know how to use it
rsdoran
Lifetime Supporting Member
Did you get the same message with laptop and desktop i.e. can not open com1?
You have verified you are using the correct cable? According to the manual there is a specific cable involved, assuming you are though. http://www.unitronic.com/data/uploads/U90_Ladder_Software/U90%20Ladder%20Software%20Manual.pdf
Do these units have RS485 ports that they could be set too?
You have verified you are using the correct cable? According to the manual there is a specific cable involved, assuming you are though. http://www.unitronic.com/data/uploads/U90_Ladder_Software/U90%20Ladder%20Software%20Manual.pdf
Do these units have RS485 ports that they could be set too?
TimothyMoulder
Member
This is a bit of a last resort, so use at your own risk, but it's worked for me twice:
Go to Start Menu, Control Panel, select the "system" icon, and choose the Hardware tab, then click "device manager".
In the device manager, scroll down till you see "Ports (COM & LPT) and open it up.
On Com1, do a right-button click and choose "Uninstall". Your com port will vanish.
Don't panic.
Close the Device Manager window and go back to Control Panel. Select "Add Hardware" and follow the instructions to restore your com port, fresh and squeaky-clean.
Try to connect again.
One other thing - On your communication settings for U90 software, make sure you set "Unit ID" to "Stand-Alone PLC", not "Network".
Go to Start Menu, Control Panel, select the "system" icon, and choose the Hardware tab, then click "device manager".
In the device manager, scroll down till you see "Ports (COM & LPT) and open it up.
On Com1, do a right-button click and choose "Uninstall". Your com port will vanish.
Don't panic.
Close the Device Manager window and go back to Control Panel. Select "Add Hardware" and follow the instructions to restore your com port, fresh and squeaky-clean.
Try to connect again.
One other thing - On your communication settings for U90 software, make sure you set "Unit ID" to "Stand-Alone PLC", not "Network".
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