Omron SYSMAC CJ1W-EIP21, Operation Manuals

Page: 273 / 438

11-3
11 SNMP Agent
CJ-series EtherNet/IP Units Operation Manual for NJ-series CPU Unit (W495)
11-1 SNMP Ag
ent
11
11-1-2
S
p
ecifications
When a failure or some other specific problem occurs, a status report called a trap is sent. This enables
monitoring changes in status even if the SNMP manager does not monitor the EtherNet/IP Unit period-
ically. However, traps use UDP. Therefore, you cannot check to see if the SNMP manager receives traps
from the EtherNet/IP port. Thus, depending on the network status, some traps may not reach the
SNMP manager.
The structure of SNMP messages is as follows:
SNMP Traps
11-1-2 Specifications
Item Specification
Protocol SNMP
Agent SNMPv1, SNMPv2c
MIB MIB-II
Port No. SNMP agent: 161 (UDP)
SNMP trap: 162 (UDP)
These can be changed in the EtherNet/IP Unit Settings from the Sysmac Studio.
Timing of SNMP trap opera-
tion Status reports are sent to the SNMP manager at the following times.
• When the Controller is turned ON
• When links are established
• When an SNMP agent fails to be authorized
Supported MIB commands GetRequest/GetNextRequest
11-1-3 SNMP Messages
Item Set value
Version This value gives the SNMP version.
SNMPv1: 0
SNMpv2c: 1
Community Community name for verification
PDU This depends on the PDU type.
MIB
EtherNet/IP Unit
Controller power supply
turned ON.
SNMP manager
Trap
SNMP agent
MAC header IP header UDP header SNMP message
Variable length (1,472 bytes max.)
Version Community PDU