Step 1: Identify Master Port # And Slave; Step 2: Load Number Of Bytes To Transfer - Automationdirect.com DL05 User Manual

Step 1: Identify Master Port # and Slave #

The first Load (LD) instruction identifies the
communications port number on the network
master (DL05) and the address of the slave
station. This instruction can address up to 99
Modbus slaves, or 90 DirectNET slaves. The
format of the word is shown to the right. The
"F2" in the upper byte indicates the use of
the right port of the DL05 PLC, port number
2. The lower byte contains the slave address
number in BCD (01 to 99).

Step 2: Load Number of Bytes to Transfer

The second Load (LD) instruction determines
the number of bytes which will be transferred
between the master and slave in the subsequent
WX or RX instruction. The value to be loaded is
in BCD format (decimal), from 1 to 128 bytes.
The number of bytes specified also depends
on the type of data you want to obtain. For
example, the DL05 Input points can be accessed
by V-memory locations or as X input locations.
However, if you only want X0 – X27, you'll
have to use the X input data type because the
V-memory locations can only be accessed
in 2-byte increments. The following table
shows the byte ranges for the various types of
DirectLOGIC™ products.
DL05/205/350/405 Memory
V-memory
T / C current value
Inputs (X, SP)
Outputs
(Y, C, Stage, T/C bits)
Scratch Pad Memory
Diagnostic Status
DL330/340 Memory
Data registers
T / C accumulator
I/O, internal relays, shift register bits, T/C
bits, stage bits
Scratch Pad Memory
Diagnostic Status(5 word R/W)
Chapter 4: Configuration and Connections
F
Bits per unit
16
16
8
8
8
8
Bits per unit
8
16
1
8
16
DL05 Micro PLC User Manual, 6th Edition, Rev. D
2 0 1
Slave address (BCD)
Port number (BCD)
Internal port (hex)
LD
KF201
6 4
# of bytes to transfer
LD
K64
Bytes
2
2
1
1
1
1
Bytes
1
2
1
1
10
1 1
2 2
3 3
4 4
5 5
6 6
(BCD)
7 7
8 8
9 9
10 10
11 11
12 12
13 13
14 14
A a
B b
c C
D D
4-15