2 sample plc-5 ladder logic program – Rockwell Automation DeviceNet Communications Module User Manual
Page 55
Using I/O Messaging
6-7
6.5.2 Sample PLC-5 Ladder Logic Program
Table 6.2 – Control File for Block Transfers
EN
ST DN ER CO EW NR TO RW RLEN DLEN FILE ELEM
R
G S
BT20:0
0
0
0
0
0
0
0
0
0
62
0
9
0
00
0
0
BT20:1
0
0
0
0
0
0
0
0
0
62
0
10
0
00
0
0
Figure 6.4 – Sample PLC-5 Ladder Logic Program
Sample PLC-5 program with an MD65 drive at DeviceNet node address 1.
The DeviceNet scanner gathers the drive status data via the network. The BTR in this rung
then moves the drive status data from the scanner to the N9: data file in the PLC, where:
N9:0 = Scanner Status word
N9:1 = MD65 (node 1) Logic Status
N9:2 = MD65 (node 1) Feedback
Note that the Feedback for the MD65 drive is received in Hz and not in engineering units.
For example, "300" equates to 30.0 Hz (the decimal point is always implied)
.
0000
BT20:0
EN
EN
DN
ER
BTR
Block Transfer Read
Module Type
1771-SDN DeviceNet Scanner Module
Rack
000
Group
0
Module
0
Control Block
BT20:0
Data File
N9:0
Length
62
Continuous
No
Setup Screen
BTR
This rung enables the DeviceNet scanner.
0001
N10:0
0
1771-SDN
Scanner
Enable bit