Automationdirect.com Stellar SR44, User Manual

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6.7.2 – Direct LOGIC PLC Example Program
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This
Direct LOGIC ladder program example works with the MWX and MRX instructions found in
the DL06 and DL260 PLC platforms.
(The DL06 and the DL260 can do RS-485 directly out of port 2.)
This program is for illustrational purposes only, and is not intended for a true application.
1
The first 2 rungs monitor comm attempts and errors for troubleshooting. Counter CT0 counts the attempts by both MRX
and MWX instructions, and CT1 counts errors. CT0 will normally be counting rapidly, while CT1 will be counting very
infrequently, if at all. If both counters are counting up, then there are problems which could be in addressing, wiring,
or PLC/SR44 setup.
Port 2 Busy
SP116
CT10
3
Status Comm Interlock
Status Comm Intlk
C10
MRX
CPU/DCM Slot :
Port Number :
Slave Address :
Function Code :
Start Slave Memory Address :
Start Master Memory Address :
Number of Elements :
Modbus Data type :
Exception Response Buffer :
K2
K1
K40009
VC100
K1
V400
03 - Read Holding Registers
584/984 Mode
CPU
CNT
CT10
K999
2
Port 2 Error
SP117
CT11
CNT
CT11
K999
This rung will be doing nearly all the Comms with the soft starter.
It reads the Status Bits from the soft starter, from P8 and P9. Note that 8 is added for the starting address of 40001,
40001 + 8 (P8's address), and the result is 40009 for the "Start Slave Memory Address" field in the MRX.
P8 and P9 are read as one 16-bit word, and they are stored as a word starting at C100, so the bits C100-C117 will reflect
the status of the starter, and those bits can be used in ladder as desired.
Updates the Soft Start
Time (P12) value of
the SoftStart.
Enable Ramp Comm
C11
Port 2 Busy
SP116
Status Comm Interlock
Status Comm Intlk
C10
SET
Chapter 6: Serial Communications
SR44 Series Soft Starter User Manual
1st Ed, Rev B 07/31/2019