ExcelLink

[can]

Hi. Recently played around with ExcelLink version 2 and found that it's a great program. However, I'm wondering how to write to the output of the PLC from Excel sheet since it's one of the option in Excel Link. Tried reading and writing to DM and it works but failed for writing to output and counter. Any ideas? Thank you.

[support]

Are the outputs already controlled by the program? If so then whatever you write to the output will be overridden by the PLC program in the next I/O scan and therefore the output will not be turned ON or OFF according to what you set in the ExcelLink.

[can]

I just load a blank program in and try but still cannot work. I use the example program by excel link and few outputs turn on when the cell in excel shows 40.. how does it work?

Regards?

[support]

ExcelLink can only write the whole 16-bit word into the output area and not a single bit at a time. A number such as 40 decimal is equivalent to 0028 (HEX) or 0000 0000 0010 1000 (BIN). This means output 4 and 6 will be turned ON. Is that what you have observed?

If you want to be able to affect one bit at a time, then you need to use ExcelLink to write to a DM area and inside the PLC program you can check the value of the DM and turn ON/OFF a single output using the SETIO command.

[can]

Hi. This is what I observe and do not understand. Thanks a lot. You have been most helpful.

[can]

Hi. Excellink seems to be delayed when I run it through USB to 232 cable. The sample program is showing 10,11, pause a while, then jump to 18 when it's supposed to read the plc constantly. Is it the cable problem? Will excellink be more reactive if I change to communicate via 485? I'm thinking of using excel and excel to act as an Hmi for a machine but the slow response and inconsistancy is scaring me. Is it possible to solve the problem?

Thank you.

[support]

Do you get a smooth online monitoring via the RS232 port and TLServer? A good indication will be to view the RTC on the View Variable screen. If the RTC is updating almost every second you do have a good communication between the PLC and the PC.

[can]

Although the communication is good, but the updating of the excel sheet is not that smooth. Any idea how to make it smooth and instant? Thanks

[support]

What is the period you define for the reading? The ExcelLink software send request to TLServer to read the relevant data and then pass the data to Excel to display. There are many factors involved.  If the period is long or too much data is being read in another action  (say to fill a big table) then the ExcelLink needs time to execute the big action and by the time it comes to execute the single data read it may be a while.

If your purpose is to capture rapidly changing data in the PLC, ExcelLink may not always be able to keep up. You can check the File Service command which let the PLC open a data file on the PC and store data there. The PLC can store data in CSV format which can be imported into Excel or any database directly.

[can]

Hi. When trying to communicate with the PLC when it's not connected to a motor controller works fine. However, when the analogue output of the PLC is connected to the input port of the motor controller, Excel Link is showing the following randomly:

1) CommException A1 received a corrupted response string from S1

2) Javalang ArrayIndex Out of Bounds Exception 16 in S1

What does all these mean? How can I ensure no breakdown in the communication between the PLC and Excel Link? Not good to be unable to control the PLC when it's in operation. Thank you for your help

[support]

Looks like electrical noise in your motor is getting into the communication line. You need to follow proper wiring guidelines by your motor controller supplier to ensure that there are flyback diodes or zener or transorb (for AC motor) to absorb high frequency transient caused by PWM signal that the motor controller uses to control the motor speed.

Also check your wiring to ensure that you are not bundling high current wire together with the communication wire or the power supply wire to the PLC in the same conduit. Cross talk can easily happen when the wires are placed next to each other.

[can]

Hi. Will using LM324 as mentioned in the other post help in reducing the noise?

[support]

No, the LM324 only provides amplified current to the motor controller but does nothing with regards to switching noise reduction on the motor wiring.