EGD Exchange Status Word Error Codes

Description

Exchange Status Word Error Codes

The Status Word allows an Ethernet Global Data user to obtain the operating status of a given exchange definition. The Status Word is changed only at the expiration of a period (Exchange Period for produced exchanges and Scan Period for consumed exchanges). If the expiration of the period occurs during the logic sweep, the update is delayed until the end of that sweep. Note that the value will be set for the entire period it is not pulsed or set for a specific number of PLC sweeps. Therefore, it is possible to have the Status Word always set to 1, implying that at the time of the period expiration, new data has arrived or was successfully produced. If a user desires some type of event notification that the transfer has occurred then it is recommended that the user edit the logic program to clear this value to 0 once a non-zero event is witnessed.

The first update of the Status Word is dependent on the type of exchange. Produced exchange Status Words are updated at the end of the first logic sweep; therefore, this value should be ignored during the first scan. Consumed exchange Status Words are updated at the beginning of the first logic sweep, implying that this value is valid immediately when the CPU transitions from Stop to Run.

Note: PACSystems does not support EGD exchange status values 16, 18, 22, 26, 28, and 30.

These exchange status values were used in Series 90 products only.

Resolution

Produced Status Words

The Status Word for a produced exchange can take on the following values:

Value - Comments

0  No new status event has occurred. The value 0 is not set by the PLC or Ethernet module. However, the PLC application program is permitted to write (only) the value 0 to the Status Word, as an aid in knowing the timing at which Ethernet Global Data production occurs. (See Status Word 1)

1  If the PLC application program had set the Status Word to 0, the transition of the Status Word to 1 would indicate that the production of data occurred at the end of the previous PLC sweep.

4  Specification Error. This error can occur only during local exchange definition setup and implies an invalid configuration parameter was received or a CPU error occurred. Potential problems are bad Destination Type, unresolvable symbolic name, or backplane communication fault. The CPU fault table will give more detail on the specific error.

10  IP Layer not currently initialized. This error can occur only during local exchange definition setup. This implies that at the time of configuration, the IP network layer was not fully initialized due to internal error or lack of a valid IP address. This is a temporary status which will change once the IP is successfully initialized.

12  Lack of resource error. This error can occur only during local exchange definition setup. This implies that resources in the network adapter prohibited successful configuration initialization. The CPU fault table should be examined to obtain more detail on the specific error.

16  Name Resolution in progress. A local produced exchange definition has specified a name for the consumer address and the local Ethernet Interface is awaiting a response from a remote name server following exchange configuration. This is a temporary status that will change when the name resolution completes. If successful, the status will become 0 (No New Data); if unsuccessful, the status will become 4 (Specification Error).

18  Loss of module error. This error can occur if the CPU no longer recognizes the network adapter within the PLC rack. A loss of module PLC Fault Table entry will also be present.

22  Ethernet Interface does not support EGD. The revision level of the Ethernet Interface does not support global data.

26  No Response from Ethernet Interface. Did not respond to establish exchange request. This fault can only occur during exchange configuration.

28  Failed to create an exchange. An error occurred (other than a resource error, no response or loss of Ethernet Interface) during exchange configuration. A PLC Fault Table entry is provided for additional information about the fault.

30  Exchange was deleted - for example, by clearing HWC.

Consumed Status Words

The Status Word for a consumed exchange can take on the following values:

Value Description

0  No new status event has occurred. Status Word = 0 occurs if the Consumed Period expires and no new data has yet arrived over the network. Also, the PLC application program is permitted to write (only) the value 0 to the Status Word, as an aid in knowing the timing at which Ethernet Global Data consumption occurs. (See Status Word 1 and 7)

1  Data Consumed. A transition to 1 (or to 7) indicates consumption of data occurred at the beginning of the current PLC sweep.

3  SNTP Error. The Ethernet Interface in the PLC producing the exchange is configured for network time synchronization (Network Time Sync parameter is set to SNTP), but is not synchronized to an SNTP server. Therefore, the timestamp associated with this data is not synchronized to the network. Note: This error condition is considered the least important of all the error codes in this section. If another error condition exists, its status code will appear in the status word.

4  Specification Error. This error can occur due to either of the following two conditions: A CPU error occurred during initialization of exchange due to a backplane communications error or the size of a received packet for this exchange definition did not match the expected size. The CPU fault table will give more detail on the specific error.

6  Data refresh error. A possible cause of this error would be if the producer has stopped producing the data or if the consumed data exchange definition is valid but the IDs or group number used do not exactly match the produced exchange definition values.

7  New data has arrived over the network but a data refresh error was encountered (data arrived later than configured update period). A transition to 7 (or to 1) indicates consumption of data occurred at the beginning of the current PLC sweep.

10  IP Layer not currently initialized. This error can occur only during local exchange definition setup. This implies that at the time of configuration, the IP network layer was not fully initialized due to internal error or lack of a valid IP address. This is a temporary status which will change once the IP is successfully initialized.

12  Lack of resource error. This error can occur only during local exchange definition setup. This implies that resources in the network adapter prohibited successful configuration initialization. The CPU fault table should be examined to obtain more detail on the specific error.

18  Loss of module error. This error can occur if the CPU no longer recognizes the network adapter within the PLC rack. A loss of module PLC Fault Table entry will also be present.

22  Ethernet Interface does not support EGD. The revision level of the Ethernet Interface does not support global data.

26  No Response from Ethernet Interface. Did not respond to establish exchange request. This fault can only occur during exchange configuration.

28  Failed to create an exchange. An error occurred (other than a resource error, no response or loss of Ethernet Interface) during exchange configuration. A PLC Fault Table entry is provided for additional information about the fault.

30  Exchange was deleted - for example, by clearing HWC.