GE SRTP Troubleshooting

General Troubleshooting

 Review the General Troubleshooting page for basic tips and getting help.

Troubleshooting By Error Message

Reference Memory Read Errors (Message Type 3)

Error response received. Item reference address is out of range.

Description: The PLC refused the reference memory read because the PLC does not have that much space in the memory segment that you are asking for.

Action/Resolution: Use vendor software (ex. Proficy Machine Edition) to verify that the memory offset that you are asking for actually exists on the PLC.

Error response received. Invalid request. If you are trying to access W this is not supported on this PLC

Description: The PLC refused the reference memory read because it does not have %W memory.

Action/Resolution: Make sure that you are communicating with a PACSystems PLC.

Error response received. Unable read reference address

Description: This is a generic error indicating that a reference read failed.

Action/Resolution: Use vendor software (ex. Proficy Machine Edition) to verify that the memory offset that you are asking for actually exists on the PLC. If that does not work, copy the section of the log file with this error and e-mail to tech support for packet analysis.

Symbolic Handle Read Errors (Message Type 5)

Error response received. Invalid symbol path

Description: The driver was unable to resolve handles to the symbolic variables that you are asking for because the path to the Protocol Variable Table is incorrect.

Action/Resolution: Uncheck the protocol option Protocol Options>Override Retrieved Symbolic Variable Pathname with Manual Setting and do another demand poll.

Error response received. Symbolics not supported on this PLC 

Description: The PLC refused the symbolic handle request because the PLC does not support symbolic variables.

Action/Resolution: Make sure that you are communicating with a PACSystems PLC.

Symbol Name: ENIU10_XFER_PRI_INPUTDISCRETE[23] Not Found. This symbolic has either not been published externally or does not exist on the PLC

Description: The CPU on the PLC cannot find the symbolic variable that you are attempting to poll.

Action/Resolution: Verify that the symbolic variable you are trying to poll has been downloaded to the PLC and that the variables’ Publish property is set to External in the vendor software.

Unit length in bytes for A301A.PV is: 4. Requested length in bytes is: 2. Adjust the requested number of bytes to pull for symbolic

Description: The PLC found the symbolic variable name “A301A.PV” but the modifier that you have chosen does not have the correct number of bytes. The number of bytes in the modifier must match the number of bytes extracted from the PLC.

Action/Resolution: There are two ways to find the correct modifier: a) use the vendor software to check the symbolic variable in question and match-up the variable’s type with the correct GESRTP modifier, or b) experiment with different modifier types that have the same number of bytes as reported by the error message.

Error response received. Failed symbol lookup

Description: This is a generic error indicating that the symbol handle read failed.

Action/Resolution: Copy the section of the log file with this error and e-mail to tech support for packet analysis.

Symbolic Value Read Errors (Message Type 6)

Error response received. Failed symbol value read. Symbol handles and meta-data are obsolete. New SYMBOL_LOOKUP required

Description: The handles to the symbolic items that you are polling have changed. This is usually caused by a download to the PLC. ACM GESRTP must re-acquire these handles before it can continue polling symbolic item values.

Action/Resolution: Either use the “Reset All Symbolic” command or uncheck Protocol Options>Do NOT Reset All Symbolic Variables on Value Read Failure and do another demand poll. This will re-poll all symbolic handles.

Error response received. Failed symbol value read

Description: This is a generic error indicating that the symbolic value read failed.

Action/Resolution: Copy the section of the log file with this error and e-mail to tech support for packet analysis.

Write request failed. Insufficient privilege level

Description: The PLC has four privilege levels. The ACM Driver was unable to do the write because the PLC has a level two password in place. At this time the ACM GESRP driver does not support password logins.

Action/Resolution: Remove the password on the PLC for privilege level two access.

Write request failed. Error response (0xd1) indicated in response byte 31 (byte 7 of the mail buffer)

Description: This is a generic error indicating that the write failed.

Action/Resolution: Copy the section of the log file with this error and e-mail to tech support for packet analysis.

Task-Based Troubleshooting

Are you unable to read from a reference address excluding the %W memory segment?

• Host Address Port (should be 18245). See Configuration.
• Destination Node (should be default of 3600). See Configuration.
• Bytes Per Request (should be default of 2048). See Configuration.
• Verify that the memory offset is within the bounds of the PLC. 
• Verify that you are using the correct item tag modifier for the data you are reading.

Are you unable to write to a reference address excluding the %W memory segment?

• Verify that the item has Good quality. 
• Verify that the value is within range and of correct type (see memory segment table). 
• Verify that you have permissions to write to the PLC (privilege level > 1). 
• Verify that the logic in the controller is not overwriting the item. 
• Verify that the memory offset you are trying to write to is not forced by the PLC.

For PACSystems family PLCs only

Are you unable to read from the %W memory segment?

• Verify that the memory offset is within the bounds of the PLC. 
• Verify that you are using the correct item tag modifier for the data you are reading. 
• Verify that you are using a PACSystems family PLC.

Are you unable to write to any reference address in the %W that you can poll?

• Verify that the item has Good quality. 
• Verify that the value is within range and of correct type (see memory segment table). 
• Verify that you have permissions to write to the PLC (privilege level > 1). 
• Verify that the logic in the controller is not overwriting the item. 
• Verify that the memory offset you are trying to write to is not forced by the PLC.

Are you unable to read any symbolic variables that have been downloaded to the PLC?

• Verify that if Protocol Options>Override Retrieved Symbolic Variable Pathname with Manual Setting is checked that you are using the correct path (should be blank in almost all cases). See Configuration.
• If Protocol Options>Do NOT Reset All Symbolic Variables on Value Read Failure (See Configuration) is checked and you have downloaded to the PLC while GESRTP items are polling, use the Reset All Symbolic Items command. 
• Verify that the symbolic variable exists on the PLC. 

• Verify that the symbolic variable that you are trying to poll is set to “Publish External” on the PLC. 
• Verify that the modifier in the tag name matches the size of the symbolic variable on the PLC. 
• Verify that you are using a PACSystems PLC.

Are you unable to write to any symbolic variables that you can poll?

• Verify that the item has Good quality. 
• Verify that the value is within range and of correct type. 
• Verify that you have permissions to write to the PLC (privilege level > 1). 
• Verify that the logic in the controller is not overwriting the item.