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Tag Reference |
The following parameters are used for Tags:
•Device: Name of an agent registered on the SNMP Device Config tab
•Item: Object identifier or OID. This parameter can also contain 3 additional formatters:
- ReadCommunity:OID = Specifies a different read community for this tag
- TableOID[Row] = When using a block, pointing to a table OID, it is possible to specify with brackets a table row to be returned, discarding other rows found. If a row is not specified, all rows will be returned.
- WalkTable: TableOID = Instruction to get all table cells in a single IOTag
•N1: If this parameter is different from 0 (zero), this indicates that the Tag is only updated using a Trap message, not by performing a communication by polling.
•N2: Allows indicating one of the communities declared in the device's Read Community option, by using an index starting at 0 (zero). For example, when declaring communities "A;B;C" at the device, at set in a tag the N2 parameter equal to 2 (two), then the "C" community is used for reading this tag. The write community will be always the one defined at the WriteCommunity option at the device configuration.
Available options for Tag parameters
ParamDevice |
ParamItem |
Read or Write |
Description |
|---|---|---|---|
Agent, such as "router-001" |
OID, such as 1.3.6.1.2.1.37.1.2.1.1.1 |
Read/write |
Any system Tag, which is read according to the configured scan. If the N1 parameter is different from 0 (zero), this Tag is only updated when receiving a Trap with that variable.
The OID that ends up with ".0" represents a scalar variable. The OID specified with an index between brackets like 1.3.6.1.2.1.37.1[1] corresponds to a table column with the row specified at the index, in this case [1]. In this case, a search is made for all OIDs lexicographically found at this table column, returning the result at the same format explained for the option WalkTable explained below. |
(same as the previous one) |
Community:OID |
Read |
Users can indicate the name of a community to use when reading, such as "public:1.3.6.1.2.1.37.1.1" |
(same as the previous one) |
TableOID |
Read |
The TagBrowser window offers the SNMP Table objects as Blocks, where each element corresponds to a table column. The Item property is configured with the table OID. When the block is read, the driver searches for all table rows, returning all of them in a list. The user can process the contents of each row (with the value of each respective column) through the OnRead block event.
As an example, if a table contains 5 rows, the OnRead block event will be called 5 times. |
(same as the previous one) |
TableOID[Row] |
Read |
Based on the previous item, when adding a row index between brackets to the item block field (associated to a table OID), the reading will return only the defined row, if existing. |
(same as the previous one) |
WalkTable:OID |
Read |
The WalkTable: instruction indicates that this Driver must traverse all OIDs lexicographically found after an initial OID informed in the Item parameter, by using the SNMP command GetNextRequest. The result is returned as a String formed by a sequence of "OID = value" combinations separated by semicolons, such as "1.3.6.1.2.1.37.1.2.1.33.1 = 1260 ;1.3.6.1.2.1.37.1.2.1.33.2 = 'Fast Ethernet Switch'" |
(same as the previous one) |
ServerStatus |
Read |
Returns the internal status of the connection with an agent. Possible values are 0: No communication or 1: Normal communication |
Any name (cannot be empty) |
UpdateConfig |
write |
Recreates all device connections from the current parameter definition, which can be changed through the write of an array of parameters and values.
See more information at Documentation of I/O Interfaces |