Rockwell-automation 1771-IFE ANALOG INPUT MODULE Bedienungsanleitung PDF herunterladen (Seite 37)

4–5Configuring Your Module

'&"! )  $'$( 

The real time sampling (RTS) mode of operation provides data

gathered at precisely timed intervals for use by the processor. BTW

word 3 bits 11–15 (13–17 octal) are used to set the real time

sampling interval.

RTS is invaluable for time based functions (such as PID and

totalization) in the PLC. It allows accurate time based calculations in

local or remote I/O racks. In the RTS mode the module scans and

updates its inputs at a user defined time interval (T) instead of the

default interval. The module ignores block transfer read (BTR)

requests for data until the sample time period elapses. The BTR of a

particular data set occurs only once at the end of the sample

period and subsequent requests for transferred data are ignored

by the module until a new data set is available. If a BTR does not

occur before the the end of the next RTS period, a time-out bit is set

in the BTR status area. When set, this bit indicates that at least one

data set was not transferred to the processor. (The actual number of

data sets missed is unknown.) The time-out bit is reset at the

completion of the BTR.

Set appropriate bits in the BTW data file to enable the RTS mode.

You can select RTS periods ranging from 100 milliseconds (ms) to

3.1 seconds. Refer to the table below for actual bit settings. Note

that the default mode of operation is implemented by placing all

zeroes in bits 11–15 (13–17 octal).

Table 4.E

Bit Settings for the Real Time Sample Mode

Decimal Bits 15 14 13 12 11

Sample Time Period

15 14 13 12 11

Sample Time Period

Octal Bits 17 16 15 14 13

Sample Time Period

17 16 15 14 13

Sample Time Period

     "  '& %&&!%      %

      %      %

      %      %

      %      %

      %      %

      %      %

      %      %

      %      %

      %      %

      %      %

     %      %

     %      %

     %      %

     %      %

     %      %

     %      %

'& &&!%  !)! !#'&% )  %

$!& !#'&% )  %

Real Time Sampling

1 2 ... 32 33 34 35 36 37 38 39 40 41 42 ... 81 82

Kommentare zu diesen Handbüchern

Keine Kommentare

Rockwell-automation 1771-IFE ANALOG INPUT MODULE Bedienungsanleitung Seite 37

Kommentare zu diesen Handbüchern

Verwandte Produkte und Handbücher für Ausrüstung Rockwell-automation 1771-IFE ANALOG INPUT MODULE