Omron ETHERNET DIRECT DR 170 14 - Manual (Page 31)

Klinkmann Automation Omron Ethernet DAServer 29
Omron Ethernet DAServer Ver 1.x User Manual Rev 1.4 17014m14
The Device Group parameters dialog can be used to configure preferred Read mode and
Write optimization mode.
If Memory Area Read is checked (default setting), then Server uses Memory Area Read
FINS commands and maximum (Read FINS Message Maximum Size – 14) / 2
consecutive words can be read from this Controller by one read command.
If Multiple Memory Area Read is checked then Server uses Multiple Memory Area Read
FINS commands and maximum 128 non-consecutive words (also from different memory
areas) can be read from this PLC by one read command.
Note: Even if Multiple Memory Area Read is configured - several memory areas are still
accessed by general read commands.
If Single Write option is checked, then for each new write value a separate write
message is created. The values in the PLC are changed by the DAServer in the same
sequence as they are changed in the user (client) application. With this option the data
update rate is low if application changes values very frequently, but sequence of value
changes are guaranteed.
If Last Msg Multiple Write option is checked, then the same message can be used for
the writing of new values into the consecutive memory addresses of the same memory
area (for example, into D0, D1, D2...). Up to 124 consecutive values can be included in
the same write command. The new value can be added only to the end of last write
message. Therefore some values may be written into the PLC memory simultaneously
even if the client application changes them step-by-step. With this option writing speed
can be seriously increased, and sequence of value changes are partly guaranteed
(several new values could be written into PLC memory simultaneously while application
change it step-by-step). For example, the client application sequentially changes the
values of following 248 items: D0, D1, ... , D247 and the values of following 248 items:
500R, 502R, ... , 994R. In this case the DAServer creates only four write messages to
write the new values for all the changed items. If the values of the same Items are