DL205 User Manual, 4th Edition, Rev. B
5–191
Chapter 5: Standard RLL Instructions - Intelligent I/O
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A
B
C
D
Intelligent I/O Instructions
Read from Intelligent Module (RD)
The Read from Intelligent Module instruction reads a block of data
(1 to 128 bytes maximum) from an intelligent I/O module into the
CPU’s V-memory. It loads the function parameters into the first and
second level of the accumulator stack, and the accumulator by three
additional instructions.
Listed below are the steps to program the Read from Intelligent module function.
Step 1: Load the base number (0 to 3) into the first byte and the slot number (0 to 7) into the second
byte of the second level of the accumulator stack.
Step 2: Load the number of bytes to be transferred into the first level of the accumulator stack.
(maximum of 128 bytes)
Step 3: Load the address from which the data will be read into the accumulator. This parameter must
be a HEX value.
Step 4: Insert the RD instruction which specifies the starting V-memory location (Vaaa) where the
data will be read into.
Helpful hint: — Use the LDA instruction to convert an octal address to its HEX equivalent
and load it into the accumulator when the hex format is required.
NOTE:
Status flags are valid only until another instruction uses the same flag.
In the following example when X1 is on, the RD instruction will read six bytes of data from
an intelligent module in base 1, slot 2 starting at address 0 in the intelligent module and copy
the information into V-memory locations V1400–V1402.
þ
þ
þ
þ
230
240
250-1
260
Sta
nd
ard
RL
L
I
n
s
tr
uc
t
io
n
s
V
aaa
R
D
.
Discrete Bit Flags
Description
SP54
On when RX, WX, RD, WT instructions are executed with the wrong parameters.
Operand Data Type
DL230 Range
DL240 Range
DL250-1 Range
DL260 Range
aaa
aaa
aaa
aaa
V-memory V
All (See page 3 - 53)
All (See page 3 - 54)
All (See page 3 - 55)
All (See page 3 - 56)
Direct
SOFT
Handheld Programmer Keystrokes
LD
K0102
X1
The constant value K0102
specifies the base number
(01) and the base slot
number (02)
LD
K6
The constant value K6
specifies the number of
bytes to be read
LD
K0
The constant value K0
specifies the starting address
in the intelligent module
RD
V1400
V1400 is the starting location
in the CPU where the
specified data will be stored
V1401
V1402
V1403
V1404
V1400
Data
12
34
56
78
90
01
Address 0
Address 1
Address 2
Address 3
Address 4
Address 5
CPU
Intelligent Module
1
B
ENT
0
A
STR
$
SHFT
ANDST
L
3
D
SHFT
ORN
R
PREV
4
E
0
A
1
B
0
A
2
C
ENT
6
G
SHFT
ANDST
L
3
D
PREV
ENT
0
A
SHFT
ANDST
L
3
D
PREV
ENT
3
D
1
B
0
A
ENT
3
1
4
2
7
5
8
6
0
9
1
0
X
X
X
X
X
X
X
X
DS
Used
HPP Used
