PLC Freezing Problem

[sparks32]

I have a weird freezing problem with a fx2424.
It only ever happens when i trying to control it via online monitoring or the hmi web app.
I loose all connection with the plc end it appears to freeze the whole plc's operation.
It happens so often that i can't really trust it to do anything unless I do not attempt to establish communication with it of any kind once it is up and running.
there are no error lights on at all. the latest freeze occurred when i tried to send an IR signal with the web AP to a 9 LED emitter and it froze the output (output 5) on the on position.
I used a camera and the 850nm LEDs are lit up. also i wrote a test program to see if the problem was just a communication one and it seems that the plc has crashed completely.
if i switch off the power then turn it back on it fixes it self until i try to connect to it and i would say 1 in 3 times it crashes
what could be going on?

[support]

When you run online monitoring without activating any I/Os, does it crash?  If it crashes only when a certain I/O is activated when you are online monitoring then we can zoom in to the function that was run when the I/O is triggered from online monitoring to find out what went wrong.

If you transfer a demo program from the "samples" folder into the PLC and run online monitoring and click on the I/Os to force some events, does it crash?

If the crash only happens to the program you wrote, then we would like to examine your program code to determine what could have led to the crash.

Also there are new upgrades to the Fx PLC firmware and may fix some earlier bugs that could crash the program for certain program loop structure that could trigger the bug. Please email to support@triplc.com for instructions to upgrade your Fx2424 firmware. Please include your purchase records (Invoice number or the company name or the person who purchased the Fx2424)

[sparks32]

When the crashes happen it is as far as i remember when i activate I/Os. but there is no particular one that causes it. sometimes it happen whens communication slows down. like for instance i activate and I/0 and have to wait 5 to 10 seconds for the PLC to comply.
The communication drops out and a dialogue box pops up and tells me to check corporate firewall. sometimes I can re establish a connection a few minutes later and other times i need to power it down after about 2 days of being unable to connect. Most of the time the program continues to run but it i'm left unable to connect to it.
It happens with the example programs and programs I have written.
I find that there are other things to that are buggy like for instance i have an lm34 reading converted to    
 °C telling me that the temprature is 22 °C  stored in DM[100] and I have written
setlcd 0,1, chr$(1)
setlcd 0,1, chr$(12)
setlcd 1,1, " Room temp is  " + str$(dm[100]) + chr$(223) + "C"
it displays on both the WEB AP and ONLINE MONITOR screens
Room temp is 22 BOC
 instead of
Room temp is 22 °C
I believe the r81 on the plc's hardware info stands for firmware revision 81. my  Itrilogi software might be corrupted so I guess it wouldn't hurt to update the firmware and get get the Itriogi 6&7 file off you guys again.

[support]

1) In your first post you said the PLC froze the whole operation,  but in your second post you said the PLC continues to run except you can't connect to it via the Ethernet. The two situations are quite different.

If the PLC continue to run the program it means the processor did not crash,  then what you encountered was a networking issue. The most likely cause is all the Ethernet ports in the PLC may have been occupied. Did you have a browser  running the webapp opened? Browsers can be quite notorious and some will quickly make up to 4 connections with the PLC and therefore use up all its F-server connection, leaving no more free Ethernet connection for the i-TRiLOIG. You can try to close all the browsers to make sure that the port are closed and wait the opened port to time out (default is 20 seconds, and this can be changed via the iTRiLOGI Ethernet and ADC Configuration). If you are then able to connect to the PLC then that confirms that the cause is the Ethernet port being occupied.

2) Regarding your second question, note that CHR$(223) is a special character that only shows as a degree symbol on the actual LCD hardware. Since it is not a standard ASCII character the browser and java JRE display it differently depending on the current font encoding. So it is best to avoid using such special character unless you want to modify the core javascript used by 0.htm to trap the special code and substitute with the degree symbol.

3) Note that if your PLC has firmware r81 that means it is the older firmware found on the F2424 PLC and not Fx2424. The firmware on F2424 only can be programmed by TL6 and it will not support the floating point features available in TL7.  Only the new Fx PLC firmware supports the floating point capability on TL7.