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1.
INTRODUCTION
MELSEC-A
1.
INTRODUCTION
This manual explains the specifications
and methods for manipulating and
programming the A64RD3C/4C (hereafter called the A64RDC) platinum
temperature-measuring resistor
P t l
00
temperature input module. This
module, is used for the following three combinations:
(1) Combined with the A2CCPU
(2)
Combined with the AnACPU (using dedicated instructions) and the
AJ71 PT32-S3
(3) Combined with the ACPU and the AJ71 PT32-S3
The A64RDC converts temperature data from a platinum temperature-
measuring resistor JPt100 or Pt100 (hereafter called the Ptl00)
to
either
16
or 32 bits of signed binary data. 16 bits of signed binary data are expressed
to the first decimal place. 32 bits
of
signed binary data are expressed to the
third decimal place. Fig. 1.1 shows the temperature measuring process.
The A64RD3C module uses three wires to connect with a Pt100.
The A64RD4C module uses four wires to connect with a Ptl00.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
:
(1) Combined with an A2CCPU
I
Pt
(3)
temperature
value
Data transfer
'
i
(2) Combined with an AnACPU
I
(using dedicated instructions)
:
and an
AJ71 PT32-S3
i
I
/
I
AnACPU
(
2
)
7
5
Buffer
memory
Detected
temperature value
- _ - -
j
I
Master
1
(y]
1
j
I
module
temperature
;
I
(3) Combined with an ACPU
j
I
and an
AJ71 PT32-S3
Detected
value
L _ _ - _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ - - - . - - - - - - - J
Master module: AJ71 PT32-S3
(1) A change in the ambient temperature of the Ptl00 changes the resistance value.
(2) Temperature data is stored as a detected temperature value in buffer memory.
(3) A detected temperature value stored in A64RDC buffer memory is read
by the PC CPU.
Fig. 1.1 Temperature Measuring Process
1 - 1
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