SNMP is a standard Internet protocol for managing routers, switches, printers, and other network connected devices.
The Fernhill SCADA SNMP Client driver acts as an SNMP Manager sending requests to one or more SNMP Agents. Using the driver you can map I/O Data Point Tags to objects in SNMP Agents. Tag values can be read at a fixed interval, or on demand, or both.
You can use the WriteValue Tag Command to send a SetRequest to the SNMP Agent.
The SNMP Client Driver supports these versions SNMP:
The driver supports these SNMP data types:
| SNMP Data Type | Description |
|---|---|
| INTEGER | 32-bit signed integer -2147483648 to +2147483647. |
| OCTET STRING | Single byte character string up to 65535 characters. |
| OBJECT IDENTIFIER | ASN1 Object identifier. |
| IpAddress | Version 4 IP address. |
| Counter32 | 32-bit counter value 0 to 4294967295. |
| TimeTicks | 32-bit elapsed time 0 to 4294967295. One unit represents 10 ms. |
| Unsigned32 | 32-bit unsigned integer value 0 to 4294967295. |
| Counter64 | 64-bit counter value 0 to 18446744073709551615. |
The SNMP Client driver provides these tag types:
| Icon | Tag Type | Version | Description |
|---|---|---|---|
| SNMP Agent Connection Tag | 1.3 | A connection to an external SNMP Agent (router, switch, printer, or network device). |
You can use these I/O Data Point Tags to represent individual data points in the SNMP Agent:
| Icon | Tag Type | Version | Description |
|---|---|---|---|
 | I/O Analog Data Point Tag | 3.12 | Maps an Analog Data Point Tag to an external data source. |
 | I/O Digital Data Point Tag | 3.12 | Maps a Digital Data Point Tag to an external data source. |
 | I/O String Data Point Tag | 3.12 | Maps a String Data Point Tag to an external data source. |
 | I/O Word Data Point Tag | 3.12 | Maps a 16-bit Word Data Point Tag to an external data source. |
 | I/O Double Word Data Point Tag | 3.12 | Maps a 32-bit Double Word Data Point Tag to an external data source. |
 | I/O Long Word Data Point Tag | 3.48 | Maps a 64-bit Long Word Data Point Tag to an external data source. |
I/O Data Point Tags use the IOItemName property to define how the tag is mapped to the data source. In I/O Data Point Tags mapped to the SNMP Driver the IOItemName property is an ASN1 Object identifier.
For information about how to discover suitable values for the IOItemName property see SNMP Driver Object Identifiers.
All I/O Data Point Tags have a TagErrorCode property that indicates any error updating the tag value. The SNMP Driver defines additional values for this field. See SNMP Client I/O Data Point Tag Error Codes for possible values for the TagErrorCode property.
For information about other drivers available in Fernhill SCADA.
For the meaning of terms used in Fernhill SCADA.