4 Pump Filler
In the folowing sections I will describe how to design a 4 pump filling machine control.
System Description
Purpose: This system can be used to replace a old Kalishtronic`filling machine control. The Kalishtronic used a central motor to drive the pumps. Each pump was controlled by a clutch/brake. An encoder on each clutch brake would tell the central computer when to stop.
The heart of the control system will be the Omron CPM1A PLC`and the OMRON NT2S 2 line display. This makes for a very economical control system which will be hard to beat even for OEMs.
The reason I have chosen this plc is because of price. The software to program the plc and the screen is freely avalable.
Parts:
PLC: OMRON CPM1A Part #:
Display: OMRON NT2S
1 Green Start Push Button NO
1 Red Stop Push Button NO
1 Blue Reset Push Button NO
1 Estop Push Button NO/NC
1 main contactor
4 SPDT relays (used for clutch/brake)
1 24vdc power supply
(kalishtronic used a transformer and bridge for the power supply, scrap this system)
1 main switch
1 set of main fuses
By: Joe Tavormina
joetavormina@yahoo.com
Note: This control sytem is for a 4 pump filler only and can not be expanded. In another section, I will present a new design for a six pump machine which will be expandable to 12 pumps. The system will use the Siemens S7- 226 PLC.
Update: Aug.10,2004
NEW PLC with up to 8 + 4 high speed counters: PANASONIC FP-X
With this PLC it becomes very easy to replace Kalish CPUs for less than $500. I will post a design for this soon. In the past I have rated the PLCs in order of their ability to replace the Kalish CPU by speed and price. This PLC seems like it will move to the top spot.
1. PANASONIC FP-X
2. Siemens CPU224
3. Mitsubihi FXo
Update: Sep. 7,2005
I found a small circuit on the web which can be used as a means of counting the pulses from a motors magnetic field. The circuit is a design by Roman Black. You can visit his website for more information.
PLC Program
The PLC program is written in grafcet. The program will show how to use the high speed counters of the cpm1a.
Update: Dec. 15,2005
I came accross a new sensor which is used to measure the viscosity of a liquid. If the feedback of this sensor is measured by the PLC the filling parameters can be modified to suit the thickness of the liquid.
PLC Program Description
4 interupts are used for the counter
Update: Oct. 8 ,2006
Panasonic released a low cost touch screen. The GT21 is available for $350 with cable and programming software. Panasonic also released a new series of FP-X PLCs with transistor outputs. It is now possible to design a control for a 12 pump filler for under $700.00 plus motors. If you would like a design layout please email me. I will post drawings and programs later on..Below is a sample animation i created for the panasonic screen that I used as a screen saver.