Operation Using A Programmable Logic - Graco ProMix PD2K Operation

Operation Using a Programmable Logic Controller (PLC)
Digital Inputs Inputs
Digital Digital Inputs
• Safety Safety Interlock Safety Interlock: This normally open contact works Interlock
like a soft emergency stop button. If the ProMix
PD2K reads the input as CLOSED it interrupts
system operation and removes power from the
pumps regardless of the current operating mode.
If the input is read as OPEN, the system operates
normally
NOTE: This digital input is always enabled.
NOTE: NOTE:
Do not toggle this input to put the system into
Standby mode.
• Gun Gun Gun Trigger Trigger Trigger #1 #1 and #1 and #2 and
(maintained) contacts provide a signal to the Mix
Units to indicate whether or not a spray device is
triggered. These inputs provide timing for alarm
functions and also drives the flow control algorithm.
If an input is OPEN the Mix Unit operates as
though the spray device is off. The input must
be maintained CLOSED to signal that the spray
device is triggered.
NOTE: The Gun Trigger discrete inputs must be
NOTE: NOTE:
enabled individually via
on the ADM. If it is set to 'Network' the discrete
input is ignored and the spray device trigger signal
is handled via the network communications.
If enabled, it is imperative that this signal be sent
any time the spray device is triggered. Without the
signal, the flow control features will not work.
PD2K Discrete Input
24
#2: These normally open #2
System Screen 4, page
4–20 mA 4–20 4–20 mA Flow mA
O = Output
R = Return
Analog Inputs
Analog Analog
Flow Flow Control Flow Control Set Control
these 4-20 mA signal inputs are used to set and
adjust the operating flow control set point for each
Mix Unit. The ProMix PD2K scales the set point
linearly from 0 to the Max Set Point setting (see
System Screen 4, page
• In In In Flow Flow Control
Flow
cc/min, a 4mA signal is 0 cc/min and a 20mA signal
is 500 cc/min.
• In In In Pressure Pressure Control Pressure
500 psi, a 4mA signal is 0 psi and a 20mA signal
is 500 psi.
NOTE: The Flow Control discrete inputs must be
NOTE: NOTE:
enabled individually via
on the ADM. If set to 'Network' the discrete input is
ignored and set point adjustment is handled via the
network communications.
71,
Flow Control Flow Control Set Control Set Set Point Point Input Point
Figure 11
PLC (4–20 mA Signal) Mix Unit #2
PLC (4–20 mA Signal) Mix Unit #1
Inputs
Inputs
Set Point Set Point #1 Point #1 and #1 and and #2 #2: When enabled, #2
Examples
71).
Control Mode: Mode: If the Max Set Point is 500
Control Mode:
Control Mode: Control Mode: If the Max Set Point is Mode:
System Screen 4, page
Input Input
,
71,
3A4486D