49
9.2.3 Connection Timeout Options
In the studio’s Project panel, navigate to
A1-ETHERNET…Ethernet…EtherNet/IP Server
. The
following configuration options will determine the actions to be taken if the connection is abnormally
terminated or lost. While this feature provides an additional level of fail-safe functionality for those
applications that require it, there are several ramifications that must be understood prior to enabling this
capability. Note that a certain degree of caution must be exercised when using the timeout feature to
avoid “nuisance” timeouts from occurring.
Run/Idle Flag Behavior
EtherNet/IP clients (such as PLCs) have the option of adding a 32-bit “run/idle” header to all class 1 (I/O)
data packets sent to devices. Bit 0 of this header is called the “run/idle flag” by the EtherNet/IP
specification, and is intended to signify when the client is in a “running” state or an “idle” state. A running
state (run/idle flag = Run) is indicated whenever the client is performing its normal processing (e.g.
scanning its ladder logic). An idle state (run/idle flag = Idle) is indicated otherwise. For example, Allen
Bradley ControlLogix PLCs will set their run/idle flag to Idle whenever their processor keyswitch is
placed in the “PROG” position, presumably in preparation to receive a new application program from
RSLogix 5000.
The behavior of EtherNet/IP devices when they receive I/O data from a controller with the run/idle flag
set to Idle is not defined in the EtherNet/IP specification. The driver allows the option of two different
behavioral responses when a run/idle flag = Idle condition is received, depending on the state of the
Invoke Timeout When Run/Idle Flag = Idle
checkbox.
•
If the checkbox is cleared (default setting), then the driver will maintain the last I/O data values
received from the client. For example, if a device mapped to the database was being commanded
to run prior to the run/idle flag being set to Idle by the client, then it will continue to run.
•
If the checkbox is checked, then the driver will perform the
Timeout Action
.
Timeout Action
Select an action from the drop down menu:
“None” ..................................No effect. The inverter will continue to operate with the last available
settings.
“Apply Fail-safe Values” .......Apply the fail-safe values as described in section 5.4.1.
9.2.4 Generic Class 1 I/O Produced and Consumed Data Settings
The Produced Data Word and Consumed Data Word objects are only applicable when connecting to
assembly instances 100 and 150 (generic I/O), which is typically the case. The Produced Data Word
defines the structure of status data sent from the inverter back to the controller (T->O, target to
originator). The Consumed Data Word objects will define the structure of the command data sent from
the EtherNet/IP controller (for example, a ControlLogix PLC) to the inverter (O->T, originator to target).
These objects allow the creation of custom-built I/O data. Up to 32 “command” parameter values can be
sent to the inverter, and up to 32 “status” parameter values can be sent back to the controller. Therefore,
up to 32 Produced and 32 Consumed Data Word objects can be created. If a consumed word offset is
not defined, that data will be ignored by the inverter. If a produce word offset is not defined, the value will
default to 0. The size of the actual I/O produced and consumed data is determined by the client upon
initial connection establishment. Since a data word utilizes 2 bytes, the size must be an even number of
bytes. The I/O data format is summarized in Table 19.
Description
This 32-character (max) field is strictly for user reference: it is not used at any time by the driver.
Produced Data Word Offset
The value from the associated inverter parameter will populate this word offset of the produced data that
is to be sent to the client. It is recommend to start at word offset 0.
Consumed Data Word Offset
The consumed data received from the client at this word offset will contain the value to be written to the
associated inverter parameter. It is recommend to start at word offset 0.
Parameter
The inverter parameter (in section 4) associated with the word offset. For the Produced Data Word
object, enter a “status” parameter to be monitored. For the Consumed Data Word object, enter a
“command” parameter that can be written.