Omron ETHERNET DIRECT DR 170 14 - Manual (Page 32)

Klinkmann Automation Omron Ethernet DAServer 30
Omron Ethernet DAServer Ver 1.x User Manual Rev 1.4 17014m14
changed in the following sequence: DM0, 500R, DM1, 502R, DM2, ... then DAServer
creates a separate write message for each new write value.
If Any Msg Multiple Write option is checked, DAServer tries to include the new write
value into any of previously created messages ignoring the sequence of data changing
in the client application.
Important! With this option maximum writing speed is achieved, but this option is not
recommended if data changing sequence is important for PLC program!
To delete device groups
Deleting a device group from the list can be performed as follows:
1. Right-click on the device group to be deleted.
2. Select the Delete command from the shortcut menu.
Note: When you select another part of the Omron Ethernet DAServer tree hierarchy, you
are prompted to save the modifications to the configuration set.
To configure default update intervals
1. To configure a default update interval for the object, right-click in the Device Groups
box.
2. Select Config Default Update Interval from the shortcut menu.
To edit update intervals
• To edit the update interval for an object, double-click its value in the Update Interval
column and make the edit.
• Update Interval is the frequency (in milliseconds) that the DAServer acquires data from
the topics associated with that device group.
• Different topics can be polled at different rates in a PLC by defining multiple device-
group names for the same PLC and setting a different Update Interval for each device
group.
Note: When you select another part of the Omron Ethernet DAServer tree hierarchy, you
are prompted to save the modifications to the configuration set.
Scan-Based Message Handling
DAServers are based on the concept of polling a hardware device for information. This
polling is driven by a need which is expressed in the form of requests from one or more
clients. Once a particular piece of information has been requested by a client, the
DAServer formulates its own request and sends that request to the hardware device. The
DAServer then waits for a response to its request. Once the information has been
received, the DAServer passes that information back to the client, and repeats the
process until all clients have ceased requesting information.
The rate at which the DAServer will poll a particular device for a specific piece of
information is defined in the device group (topic definition) inside the DAServer, using a
parameter called the Update Interval. When setting this parameter, there is always a
trade-off between the update speed of the device group and the resulting decrease in
system responsiveness.