ABB REF 54 Series Technical Reference Manual page 69

1MRS750527-MUM

)HHGHU 7HUPLQDO
Technical Reference Manual, General
The command time-out parameter is located in MAIN MENU/Communication/
General.
For more information about secured object control refer to the control function block
manuals.
6HWWLQJ WKH FRPPDQG WLPHRXW SDUDPHWHU IRU /21
FRPPXQLFDWLRQ
The correct command time-out parameter value depends on how many LON
communication inputs are in use (COMM_INx variables). If no horizontal
communication is used, 1.5 seconds shall be used as time-out.
In order to take full advantage of the secured command handling procedure, the
complete scenario must be known.
There are two scenarios:
1. Confirmed command handling with NV poll support: NV poll selected by the
LNT tool.
2. Command handling with asynchronous blockings.
&RQILUPHG FRPPDQG KDQGOLQJ ZLWK 19 SROO VXSSRUW
If LON NV polling is used for communication inputs, the time-out must be based on
the minimum time-out, and is calculated from:
amount_of_polled_inputs*poll_timeout*(retries+1)
which gives a typical minimum value of:
amount_of_polled_inputs*128ms...256ms*5
(see the LN settings and refer to the instructions given for default time-outs).
An over dimensioned longer time-out will not cause any harm, because the operation
will always be faster in real life than the maximum time-out.
On application side, the comm_in and comm_outs need to be used systematically to
ensure that exceptions to the normal operation are handled correctly (e.g. handling
of the live bits).
&RPPDQG KDQGOLQJ ZLWK DV\QFKURQRXV EORFNLQJV
Figure 4.1.13.8-1 shows the asynchronous blocking principle of sending the reserve-
output state to the block-inputs of other bays. As horizontal communication is
trusted directly, 1.5 seconds shall be used as command time-out.
For more information about asynchronous blockings refer to the horizontal
communication engineering tip in the Configuration Guideline (1MRS 750745-
MUM).
'LVSOD\ SDQHO +0,
The feeder terminal is provided with either a fixed display or an external display
module. The external display module requires a separate voltage supply from a
common source with the main unit (refer to section "Auxiliary voltage" on page 28).
For more information about the rated input voltages, refer to Table 4.2.1-2 on
page 75. A special cable (1MRS120511.001) delivered with the feeder terminal is
needed for communication between the terminal and the external display panel.
5() B
69