Parker LVD1 - Page 69

Parker Hannifin S.p.A. - Divisione S.B.C. LVD User’s Manual
69
Example 8: Inter Drive Communication
IDC (Inter Drive Communication) refers to a specific configuration of the serial port of the
LVD drive that makes it possible to interchange parameters between two or more units.
With IDC enabled (Pr26=10) if bit b99.5 is set to 1 the LVD activates a broadcast
command by sending the value of Pr81 to the address of Pr80. LVDs that receive broadcast
commands with Pr26=10 automatically set b99.5 to 1 causing automatic transmission of Pr81
to the address of Pr80 in broadcast mode. Using this potential, it is extremely simple to
connect two LVD drives in a loop via the serial ports, and a short program on the internal PLC
will suffice to start transmission at power-on and restore it in the event of communication
errors. The following example describes the PLC program required to copy parameter Pr81 of
the two drives in parameters Pr80.
Connection function
These PLC instructions must be entered on only one of the drives; both drives must have
parameter Pr26=10 to enable the IDC function.
1
3
2
4
5
6
7
8
4
2
3
1
5
6
7
8
X3 X3
drive 1 drive 2
99
drive 1 drive 2
Pr81 Pr80
Pr80 Pr81
DIV
99.5 75 74 92
99.0
SET
99.5
DIV
75 74 92
If broadcast is received
timer is set to 30mS
if time-out is present
reset serial line
and set timer
LD
99.5
DIV 75.74.92
LD 99.0
SET 99.5
DIV 75.74.92