Internal data points

This field shows when a so called generic trap was sent. The following possibilities are available:

• Coldstart
• Warmstart
• LinkUp
• LinkDown
• AuthenticationFailure
• EgpNeighborLoss

For the meaning of these terms see RFC 3418 (SNMP v2)

This element contains the values of payload elements.

To handle octet strings containing non-printable characters the config entry [snmpdrv] trapPayloadOctetStringHex can be activated.

This element contains information regarding homeless traps.

The message will be saved in following format:

<Agent name>|<AgentId>|<SNMP data type as string (SNMP data type as integer value)>|<OID>|<agent IP>

Example

• If the agent is not configured, which has sent the trap, following message will be set to the data point:

  ?|?|INT32
  (2)|1.3.6.1.4.1.8691.10.2242.11.6|192.168.152.25

  A trap has been received from a device at IP 192.168.152.25. The unknown fields for <Agent name> and <AgentId> show a '?'.

• If the agent has been configured but the OID is unknown, following message will be set to the data point:

  _1_SNMPAgent_6|6|INT32
  (2)|1.3.6.1.4.1.12148.9.1.10.0|192.168.152.18

  A trap has been received from agent _1_SNMPAgent_6 at IP 192.168.152.18 but the OID 1.3.6.1.4.1.12148.9.1.10.0 is not known inside the WinCC OA System

The SNMP agent data point type represents the configuration for an agent. The data point names are composed of a driver number, the string from the config file and the agent number. The agent number can range from 1 to "maxAgents". Normally, a data point would be named e.g. _1_SNMPAgent_5.

• bit0: Redundancy switch when a timeout occurs. Defines if an agent switch is performed if the response of a READ or WRITE request returns the timeout status.
• bit1: Redundancy switch when a keepAlive-error occurs. Defines if an agent switch is performed if a KEEPALIVE check fails.
• bit2: Driver uses getBulk requests instead of individual getNext requests.
• bit3: The connection is terminated if a USM error occurs (error code ≤ 100).
• bit4: The connection is terminated when a user USM error occurs (error code > 100).
• bit5: An alive query is performed when the configuration is changed.
• bit6: Determines whether an octet string within the browse result should be displayed in hexadecimal format (=1) or as a visible string (=0; default).

If a protocol error occurs, this data point shows the corresponding OID. Since the element is a dynText, all current not available OIDs are shown. Furthermore, the invalid bits of the WinCC OA elements are set accordingly.

Format:

errorcode#OID - ERROR: errortext

The possible error codes are:

OID errors

• 2//!< No such VB name, see error index
• 3 //!< Bad Vb
• 6 //!< No access to MIBs data
• 7 //!< Requested type was incorrect
• 8 //!< Request Pdu has inccorect length
• 9 //!< Request Pdu has wrong encoding
• 10 //!< Request Pdu has wrong value
• 11 //!< Unable to create object specified
• 12 //!< Inconsistent value in request
• 13 //!< Resources unavailable
• 14 //!< Unable to comit
• 15 //!< Unable to undo
• 16 //!< Authorization error
• 17 //!< Mib Object not writeable
• 18 //!< Inconsistent naming used

Protocol errors

• -5 //!< outstanding request timed out
• -8 //!< snmp::destroyed with oustanding reqs pending

Transport errors

• -20 //!< transport unsupported
• -21 //!< transport in use
• -22 //!< transport operation failed
• -23 //!< transport missing rights

The DPE displays the connection state of the SNMP Agent

The following applies to each Agent configured for an SNMP manager:

• On startup of the manager the value for Status. ConnState is set to FALSE.
• Configuring the first peripheral address for an agent triggers an alive check, the value of the DPE will be set to TRUE if the configured Agent is available. After this the value is updated on each alive check
• For triggering this first check the address must be set to active.

The data point element contains the response of the writing attempt of the SNMP agent. Following information is stored:

<error code>#<internal agent ID>_<OID> [ -error <error description>],

Example for a successful write process:

0#1_1.3.6.1.4.1.8691.10.2242.10.1.1.4.11

Example for an writing process error:

-5#1_1.3.6.1.4.1.8691.10.2242.10.1.1.4.11 - error: SNMP++: SNMP request timed out

The corresponding error codes can be seen in the description of the DPE element Status.ErrorOID.

This element indicates the active target the driver communicates with:

• 0: first target
• 1: redundant target

Two commands can be sent to the local agent via this element:

• Clearerror (1) deletes the ErrorOID data point and also all internal errors.
• Checkerror (2) updates the ErrorOID data point and the QueueLength element.

Defines the start-OID for querying all data of the agent. These will be written to the Browse.Result DPE.

If this DPE is left empty, the query is started with the start-OID "1.3.6.1".

It is possible to initiate several browsing requests by dpSet on this data point element. The requests are added to a queue one by one and are executed in the same order.

Basically there is no limit to the number of browsing requests in the queue. However, a browsing request is discarded if the exact same request is already in the queue.

Each browsing request is identified (see Browse.RequestId below) by the string that was set on this data point element. This means that the following requests are different and unique requests that will be added to the queue concurrently:

• “1.3.6.1.2.1.1”
• “1.3.6.1.2.1.1:7”
• “1.3.6.1.2.1.1:3”
• “1.3.6.1.2.1”
• “1.3.6.1.2.1.2”

Contains the result of the query that was started with the Browse.Start DPE. During the browsing the value of this DPE is "1 - started browsing".

Once the browsing is completed, the result contains the data of the agent. One data set always consists of three lines:

1st line: OID

2nd line: Value in a default transformation

3rd line: Data type as number#data type as text

Example with two data sets:

1.3.6.1.2.1.1.1.0
Hardware: x86 Family 6 Model 15 Stepping 8 AT/AT COMPATIBLE
4#OCTETS
1.3.6.1.2.1.1.3.0
0:00:26.60
67#TIMETICKS

Possible values for the data type:

• 2 - INT32
• 3 - BITS
• 4 - OCTETS
• 6 - OID
• 64 - IPADDR
• 65 - CNTR32
• 66 - UINT32
• 67 - TIMETICKS
• 68 - OPAQUE
• 70 - CNTR64

If the result does not contain a number of entries which can be divided by 3, then it is a state message. In this case the first line indicates the status code:

1 - query started
-1 - error

The error code and the description are contained in the second line.

For example:

-1
-5#SNMP++: SNMP request timed out

Displays the connection state of the redundant SNMP agent.

On startup of the manager, the value for Redu.Status.ConnState is set to FALSE. After the first successfully received message the state will be set to TRUE.

Commands can be sent to the driver layer via this element. This element servers for test purposes.

• Alive query (1) is sent to the connected targets

The security level describes which security measures should be used for the data exchange.

• noAuthNoPriv (1) No authentication and no encryption

• authNoPriv (2) Authentication but no encryption

• authPriv (3)Authentication and data encoding

Default value is (1).

The addressed context name on the target computer. The context contains specific MIB objects.

Per agent only one context name can be specified. If several context ranges should be queried per agent, several data points have to be created.

There are two protocols available for the authentication of the SNMP users:

• none (1) no authentication protocol
• HMAC_MD5 (2) MD5 authentication
• HMAC_SHA (3) SHA authentication
• HMAC_SHA2_224 (4) SHA2 authentication
• HMAC_SHA2_256 (5) SHA2 authentication
• HMAC_SHA2_384 (6) SHA2 authentication
• HMAC_SHA2_512 (7) SHA2 authentication

Default value is (1).

The sent data can also be encrypted in order to increase the security. For the encryption a protocol has to be selected.

• none (1): no encryption
• DES (2): DES encryption (Data Encryption Standard)
• IDEA (9): IDEA encryption (International Data Encryption Algorithm)
• AES128 (4) Advanced Encryption Standard encryption with 128 bit key
• AES192 (20) Advanced Encryption Standard encryption with 192 bit key
• AES256 (21) Advanced Encryption Standard encryption with 256 bit key

Default is (1).

• bit0: Redundancy switch when a timeout occurs. Defines if an agent switch is performed if the response of a READ or WRITE request returns the timeout status.
• bit1: Redundancy switch when a keepAlive-error occurs. Defines if an agent switch is performed if a KEEPALIVE check fails.
• bit2: Driver uses getBulk requests instead of individual getNext requests.
• bit3: The connection is terminated if a USM error occurs (error code ≤ 100).
• bit4: The connection is terminated when a user USM error occurs (error code > 100).
• bit5: An alive query is performed when the configuration is changed.
• bit6: Determines whether an octet string within the browse result should be displayed in hexadecimal format (=1) or as a visible string (=0; default).

Indicates the active target the driver communicates with

• 0: first target
• 1: redundant target

Last number of OID (Object identifier). This number is appended to the OID notification defined in the WinCC OA MIB. If you modify this DPE a trap is sent to the corresponding SNMP V3 entity by the SNMP manager.

-dbg 26 can be used to get debug information when a trap was sent.

Defines the start-OID for querying all data of the agent. These will be written to the Browse.Result DPE.

If this DPE is left empty, the query is started with the start-OID "1.3.6.1".

It is possible to initiate several browsing requests by dpSet on this data point element. The requests are added to a queue one by one and are executed in the same order.

Basically there is no limit to the number of browsing requests in the queue. However, a browsing request is discarded if the exact same request is already in the queue.

Each browsing request is identified (see Browse.RequestId below) by the string that was set on this data point element. This means that the following requests are different and unique requests that will be added to the queue concurrently:

• “1.3.6.1.2.1.1”
• “1.3.6.1.2.1.1:7”
• “1.3.6.1.2.1.1:3”
• “1.3.6.1.2.1”
• “1.3.6.1.2.1.2”

Contains the result of the query that was started with the Browse.Start DPE. During the browsing the value of this DPE is "1 - started browsing".

Once the browsing is completed, the result contains the data of the agent. One data set always consists of three lines:

1st line: OID

2nd line: Value in a default transformation

3rd line: Data type as number#data type as text

Example with two data sets:

1.3.6.1.2.1.1.1.0
Hardware: x86 Family 6 Model 15 Stepping 8 AT/AT COMPATIBLE
4#OCTETS
1.3.6.1.2.1.1.3.0
0:00:26.60
67#TIMETICKS

Possible values for the data type:

• 2 - INT32
• 3 - BITS
• 4 - OCTETS
• 6 - OID
• 64 - IPADDR
• 65 - CNTR32
• 66 - UINT32
• 67 - TIMETICKS
• 68 - OPAQUE
• 70 - CNTR64

If the result does not contain a number of entries which can be divided by 3, then it is a state message. In this case the first line indicates the status code:

1 - query started

-1 - error

The error code and the description are contained in the second line.

For example:

-1

-5#SNMP++: SNMP request timed out

Describes which security measures shall be used for the data exchange of the redundant agent.

• noAuthNoPriv (1): no authentication and no encryption
• authNoPriv (2): authentication but no encryption
• authPriv (3): authentication and data encoding

Default value is (1).

There are two protocols available for the authentication of the redundant SNMP users:

• none (1) no authentication
• HMAC_MD5 (2) MD5 authentication
• HMAC_SHA (3) SHA authentication
• HMAC_SHA2_224 (4) SHA2 authentication
• HMAC_SHA2_256 (5) SHA2 authentication
• HMAC_SHA2_384 (6) SHA2 authentication
• HMAC_SHA2_512 (7) SHA2 authentication

Default value is (1).

The sent data for the redundant target can also be encrypted in order to increase the security. A protocol must be selected for the encryption.

• none (1): no encryption
• DES (2): DES encryption (Data Encryption Standard)
• IDEA (9): IDEA encryption (International Data Encryption Algorithm)
• AES128 (4): Advanced Encryption Standard with 128 bit key.
• AES192 (20): Advanced Encryption Standard with 192 bit key.
• AES256 (21): Advanced Encryption Standard with 256 bit key.

Default is (1).

Displays the connection state of the redundant SNMP agent.

On startup of the manager, the value for Redu.Status.ConnState is set to FALSE. After the first successfully received message the state will be set to TRUE.