Configure Remote I/O Slaves
After configuring the DL250–1 or DL260 CPU’s Port 2 and wiring it to the remote slave(s),
use the following checklist to complete the configuration of the remote slaves. Full
instructions for these steps are in the Remote I/O manual.
• Set the baud rate to match CPU’s Port 2 setting.
• Select a station address for each slave, from 1 to 7. Each device on the remote link must
have a unique station address. There can be only one master (address 0) on the remote link.
Configuring the Remote I/O Table
The beginning of the configuration table
for the built-in remote I/O channel is the
memory address we selected in the Port 2
setup.
The table consists of blocks of four words
which correspond to each slave in the
system, as shown to the right. The first
four table locations are reserved.
The CPU reads data from the table after
powerup, interpreting the four data words
in each block with these meanings:
1. Starting address of slave’s input data
2. Number of slave’s input points
3. Starting address of outputs in slave
4. Number of slave’s output points
The table is 32 words long. If your system
has fewer than seven remote slave bases,
then the remainder of the table must be
filled with zeros. For example, a 3–slave
system will have a remote configuration
table containing 4 reserved words, 12
words of data and 16 words of “0000”.
A portion of the ladder program must
configure this table (only once) at
powerup. Use the LDA instruction as
shown to the right, to load an address to
place in the table. Use the regular LD
constant to load the number of the slave’s
input or output points. The following
page gives a short program example for
one slave.
DL205 User Manual, 4th Edition, Rev. B
4–29
Chapter 4: System Design and Configuration
1
2
3
4
5
6
7
8
9
10
11
12
13
14
A
B
C
D
Remote I/O data
V37700
xxxx
V37701
xxxx
V37702
xxxx
V37703
xxxx
37700
Memory Addr. Pointer
LDA
O40000
OUT
V37704
Reserved
Slave 1
Slave 7
V37704
xxxx
V37705
xxxx
V37706
xxxx
V37707
xxxx
V37734
0000
V37735
0000
V37736
0000
V37737
0000
LD
K16
OUT
V37705
SP0
Direct
SOFT
