| Introduction |
| Avoid common mistakes when starting a new GP-Pro project with a new PLC. |
| Contents
|
| 1) Configuration Information |
| 2) Communication Settings |
| 3) System Area |
| 4) Making the Test project |
| 5) Downloading |
| 6) Solving communication issues |
|
| 1) Configuration Information |
| Find the Manufacturer, PLC Series and CPU you want to connect to in the
"PLC/Device Connection Manual"
|
| Once you have located the correct CPU you can find the correct cable diagram as well as the communication settings for both
your GP/GLC and the PLC in this manual. |
| 2) Communication Settings |
| Click the "GP Setup " button in the GP-Pro PBIII Project Manager. |
| Go to the "Communication Settings" tab and adjust the communication settings to match the PLC/Device
Connection Manual and those on your PLC. |
| If you are using a protocol that supports multiple GP/GLC's or multiple PLC's make sure to go to the
"Mode Settings" tab to adjust the protocol's node number and network configuration. |
| 3) System Area |
| In almost every new project the GP/GLC is by default configured to share part of its internal memory
(the "LS Area") with the PLC. 16 Words of data from the part of the LS Area known as the "System Area"
(LS0000 -LS0019) will automatically be transferred to the PLC. The data will be transferred to 16 (16-bit)
consecutive PLC registers starting at the PLC address that is automatically set to a default address on
the "Mode Settings" tab under "System Start Address". |
| Since the PLC address entered in "System Start Address" might not (yet) exist on your PLC this default
behavior is a communication error waiting to happen. To prevent this data transfer from happening go the
"Extended Settings" tab in "GP Setup" and click the "System Area" button. Deselect all 16 checked
options. This way the functions of the system are still available but they are not transferred to the PLC. |
| 4) Making the Test Project |
| Keep your test project as simple as possible, all
you want to do is make sure the communication
settings and cable are correct and that the GP/GLC
and PLC are communicating. |
| Create just 1 Base Screen with one Bit Switch and Lamp or one Numeric Display. |
| Use a PLC address that exists in your current PLC
setup. Use the "calculator" tool in the Bit Switch
or Numeric Display setup to make sure the address
syntax is correct. |
| 5) Downloading |
| Before downloading the project go to the "Transfer Settings" option in the Transfer Window. Make sure
that the checkbox labeled "GP System Screen" is checked. Without this option selected none of the
changes made in "GP Setup" will be transferred to the GP/GLC. Also note that if you change the "Send
to" option to select Ethernet or Serial Transfer the "GP System Screen" will automatically be deselected.
Select the checkbox again if that happens. |
| 6) Solving Communication issues |
| Following steps 1 through 5 above should prevent any communication errors from occurring.
If however you do see a communication error on the GP/GLC here are the most common ones
with possible causes and solutions.
|
| Error: | 02:FF (PLC Not Connected) |
| Description: | There is no communication with the PLC |
| Cause: | - There has been no communication with the PLC for 60 seconds. |
| | - The communication cable is unplugged on the GP/GLC Side, wrong or damaged. |
| | - The RS & CS lines are not connected (or closed out on the GP/GLC side) |
| |
| Error: | 02:FE (PLC Not Responding) |
| Description: | The GP/GLC has successfully sent a message but there is no reply from the PLC. |
| Cause: | - RX & TX lines in the cable are disconnected or wrong. |
| | - The communication settings on GP/GLC do not match those on the PLC |
| | - The PLC Node number does not match the setup on the GP/GLC |
| | - When powered up simultaneously the GP/GLC might try to communicate before the PLC
is ready. Start the PLC first and power up the GP/GLC later. If this is the problem go to
"GP Setup" on the "GP Settings" tab add a value in the "Com Port Startup Delay " field.
When powered up simultaneously the GP/GLC will now wait x seconds before trying to
establish communication. |
| |
| Error: | 02:FD (Receive Data Error) |
| Description: | The GP/GLC and PLC are communicating but cannot interpret the data received |
| Cause: | - During normal communication one of the peers fails, cutting a message short |
| | - There is an issue with the protocol implementation. (Modbus Master RTU, 32 slave) |
| | - Parity settings, Start / Stop bit setup mismatch between GP/GLC and PLC |
| |
| Error: | 02:xx (PLC Com. Error) where xx is a hexadecimal error code. |
| Description: | Depends on the PLC and Protocol used |
| Cause: | The latter part of this error message is an error code sent by the PLC. |
| | Refer to your PLC manual to find out what the meaning of the error code is. |
|
| Depending on the protocol and PLC used there are more GP/GLC error codes in the 02:Fx range that are
defined by the GP/GLC. Protocol specific error codes are listed in the PLC/Device Connection Manual in
the same chapter where you found your PLC and Cable information in Step 1 of this document. |
| |
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