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84
model 3000 DeviceNet Module Manual (DN311/DN311A)
Chapter 4 Operating Procedures for the DN311 (Software)
4
READ_DT
Structural data type Intput data from slave device
READ_DT structure:
RPOL[0]
WORD type
Polling input data (0)
RPOL[1]
WORD type
Polling input data (1)
~
~
~
RPOL[127]
WORD type
Polling input data (127)
(3) Description of operation
Figure 4-18 Input/Output Data Area Batch Access Function Block Data Input/Output
(a) Use this function block when the DN311 is in run mode.
(b) When REQ is TRUE, data is input and output to and from the DN311 specified by
CH, UNIT, and SLOT. Data from two or more slave devices can be sent or
received because an input/output data area can be specified.
(c) Of the output data to the slave device written in WRITE_DT, the number of words
corresponding to N_WPOL are written in the polling output data area of the
DN311 and 4 words (fixed) in its bit strobe output data area.
WPOL[0] to WPOL[377] amd WBS[0] to WBS[3] correspond to the polling output
data area/bit strobe output data areas as shown in the table below.
Write them as appropriate to the specifications of the slave devices you are
using.
Table 4-16 WRITE_DT Composition
Output Data
Output Area Address
WPOL[0]
017AH
~
~
WPOL[377]
02F3H
WBS[0]
02F4H
~
~
WBS[3]
02F7H
DN311
Slave device
Polling
Bit strobe
Polling/bit strobe
input data area
Polling output data
area
Bit strobe output
data area
READ_DT
(RPOL)
WRITE_DT
(WPOL)
WRITE_DT
(WBS)
Input data
register area
Output
area
register
area
S controller