Rockwell Automation 1771-DMC_DMC1_DMC4_DXPS Control Coprocessor User Manual - Manual (Page 64)

Chapter 5
Developing Programs
5-4
Table 5.D
DTL Read/Write Access Functions
Function What It Does Why YouNeed It When YouUse It
DTL_READ_W Reads data from the PLCĆ5 programmableĆ
controller data table to the controlĆ
coprocessor memory
To perform a read of a
PLCĆ5 programmableĆ
controller data table
When you want to receive data from the PLCĆ5
programmableĆcontroller data table
DTL_READ_W_IDX Reads any elements of a file, one element at a
time, from the PLCĆ5 programmable controller to
the controlĆcoprocessor memory using only one
data definition
Toperform an indexed
read of a PLCĆ5
programmableĆ
controller file
When you want to receive any elements of a file
from the PLCĆ5 programmableĆcontroller data
table using one data definition
DTL_WRITE_W Writes data from the controlĆcoprocessor memory
to the PLCĆ5 programmableĆcontroller data table
Toperform a write toa
PLCĆ5 programmableĆ
controller data table
When you want towrite data toa PLCĆ5
programmableĆcontroller data table
DTL_WRITE_W_IDX Writes any elements of a file, one element at a
time from the controlĆcoprocessor memory to the
PLCĆ5 programmable controller using only one
data definition
Toperform an indexed
write toa PLCĆ5
programmableĆ
controller file
When you want to write any elements of a file to
a PLCĆ5 programmableĆcontroller data table
using one data definition
DTL_RMW_W Initiates an operation that:
• reads a data element
• modifies some of the bits
• then writes it back
Toperform a
read/modify/write to a
PLCĆ5 programmableĆ
data element
When you want the application program to
read/modify/write an element of the PLCĆ5
programmableĆcontroller data table
DTL_RMW_W_IDX Initiates an operation that reads a data element of
the PLCĆ5 processor, modifies some of the bits
based on mask values, then writes the data
element back
Toperform an indexed
read/modify/write to a
PLCĆ5 programmableĆ
controller file
When you want the application program to
read/modify/write any elements of a PLCĆ5
programmableĆcontroller file using only one data
definition
Conversion Functions
Conversion functions convert data from one format to another. When you
specify an application data type in the definition of a data item, the read,
write, and receive functions automatically convert the data from the format
in the PLC-5 programmable controller to proper format for the control
coprocessor. The data types are as follows:
PLC Data Types ControlĆCoprocessor Data Types
signed word
IEEE float
raw
byte
ubyte
word
uword
long
ulong
float
double
See Table 5.E for DTL conversion functions.