IMI Bimba PCS Assembly instructions

1
Bimba Model PCS Pneumatic Control System
Learn how to:
>Recognize the components required for a PCS system.
>Understand how the PCS components are interconnected.
>Be able to adjust Zero, Span, Deadband, Decel.
>Understand basic PCS operation.
Components required for a complete closed loop system:
>PCS electro-pneumatic controller (includes valves).
>PFC, PFCN, PTF, or PTFN cylinder.
>Air supply (70-80 psi required for proper operation).
>24 VDC fixed for PCS (regulated and filtered).
>0-10 VDC variable control voltage (clean, stable, noise free).
>DPM panel meter (for direct positioning readout).
>120 VAC line power for DPM if used.
Technical Tips
PCS-PFC Quick Set-up Instructions
The information presented is in Bimba’s best engineering opinion and should be used for reference only. Recommendations derived should be verified under actual operating
conditions. Bimba reserves the right to change specifications without prior notice.
Bimba Manufacturing
Telephone: [phone]
Email: [email protected]
www.bimba.com
To learn more, scan this QR code
with your mobile device.
Leaders in Actuation.

2
Getting Started
1. Fittings should be firmly attached to the PCS manifold and PCS
ports. Teflon tape must be used to seal the threads.
2. Connect air hoses from the PCS control to the PFC. Use Figures
4 and 5 on the right. “De-crease” in Fig. 4 goes to the front of the
cylinder, and “Increase” goes to the rear. The air supply is connected
to the middle port. The end ports are exhaust ports with no
connections.
3. Remove cover to expose the PCS control. Review all positions in the
top three terminal blocks. They are clearly marked. Electrical con-
nection to valves is not required of customer for encased controls.
Identify trim pots and LEDs, which are also clearly labeled.
4. Connect the feedback cable from the cylinder to TB2, 24 VDC
power to TB1, and the 0-10 V control signal to TB4. Power up the
DC power source, then zero and power up the control voltage.
Technical Tips
PCS-PFC Quick Set-up Instructions
The information presented is in Bimba’s best engineering opinion and should be used for reference only. Recommendations derived should be verified under actual operating
conditions. Bimba reserves the right to change specifications without prior notice.
Bimba Manufacturing
Telephone: [phone]
Email: [email protected]
www.bimba.com
To learn more, scan this QR code
with your mobile device.
Leaders in Actuation.

3
Set-up and adjustments
Set the deadband
The deadband adjustment changes the tolerance on the ending position of the PFC rod.
Smaller deadbands mean a tight tolerance and higher positioning accuracy. Higher deadbands
are required for greater loads.
1. Application sizing chart (PCS manual page 23, below) identifies “Zero Friction Deadband
Voltage” for setting deadband. The deadband setting can be varied from 0.005 to 0.500 VDC.
2. Locate TP1, TP2, SW1, and the deadband adjustment pot.
3. Move SW1 to SET position.
4. Set DMM to DC volts and measure between TP1 and TP2.
5. Adjust deadband setscrew to 100 mV initially.
6. Move SW1 to NORMAL position.
Technical Tips
PCS-PFC Quick Set-up Instructions
The information presented is in Bimba’s best engineering opinion and should be used for reference only. Recommendations derived should be verified under actual operating
conditions. Bimba reserves the right to change specifications without prior notice.
Identify LEDs and Span and Zero adjustments
LEDs indicate valve operation
1. Green LED means rod is being extended: Air is exhausted from
Valve 1 (front) and pressure is applied at Valve 3 (rear).
2. Red LED means rod is being retracted: Air is exhausted from Valve
3 (rear) and pressure is applied at Valve 1 (front).
Set the zero position
1. Set control voltage to 0.
2. Turn ZERO adjust CW until rod is in the desired retracted position (not necessarily fully retracted).
3. Red LED should not be on continuously.
Application Sizing and “Rules of Thumb”
PFC Cylinder/PCS Valve System Matching and Sizing Reommendations
TP1
TP2
Deadband SW1
LEDsSpan Zero
Bore Size PCS
MODEL
Stroke
Range
Maximum
Payload @
Average
Velocity
(Ibs.)
Maximum
Average
Velocity
Without
Overshoot
(In/Sec)
Maximum
External
Friction
(Ibs.)
Zero
Friction
Deadband
Width Per
Inch Of
Stroke
1/2
Maximum
Friction
Deadband
Width Per
Inch Of
Stroke
Maximum
Friction
Deadband
Width per
inch of
stroke
Minimum
Step (In.)
1-1/16“ (PFC-09) PCS-1 2” to 7” 1 2,75 0 0.005” N/A N/A 0,08
1-1/16“ (PFC-09) PCS-1 8” to 24” 30 4,00 5 0.004” 0,008” 0,016” 0,2-0,39
1-1/2“ (PFC-17) PCS-1 1” to 3” 2 2,5 0 0.0025” N/A N/A 0,04
Bimba Manufacturing
Telephone: [phone]
Email: [email protected]
www.bimba.com
To learn more, scan this QR code
with your mobile device.
Leaders in Actuation.

4
Technical Tips
PCS-PFC Quick Set-up Instructions
The information presented is in Bimba’s best engineering opinion and should be used for reference only. Recommendations derived should be verified under actual operating
conditions. Bimba reserves the right to change specifications without prior notice.
Set the Span adjustment or end position
1. Set control voltage to maximum (10 VDC).
2. Turn SPAN CCW until rod is in the desired fully extended position.
3. The green LED should not be on continuously.
Decel adjustment
The decel adjustment regulates the distance over which the PFC rod slows to a stop.
Low Decel settings provide fastest speeds. High Decel settings provide the most
stability for high loads. If deadband is set too low for the load, the rod will overshoot
and undershoot the target position, oscillating before settling to a stop.
1. Locate TP1, TP3, and Decel adjustment.
2. The DECEL setting can be varied from 0.5 to 13.5 VDC.
3. Adjust DECEL trim pot to 3 V between TP1 and TP3 ini-tially.
4. Turn DECEL adjust and monitor voltage with DMM.
General Procedure
1. Set-up the PCS control under load, installed in the machine. If it is not under load it will need to be readjusted.
2. Under load, vary the control voltage from 0 to 10 V. Movement should be smooth between end posi-tions with minimal chatter.
3. If there is chatter, adjust decel and deadband for optimal performance.
4. Leaks in air hoses and fittings or cracked fittings will cause erratic operation.
5. Air pressure may cause erratic operation. Pressures from 60-80 psi should yield good results.
TP1
Decel
TP3
Bimba Manufacturing
Telephone: [phone]
Email: [email protected]
www.bimba.com
To learn more, scan this QR code
with your mobile device.
Leaders in Actuation.

5
Troubleshooting Hints...
1. Air pressure should be 70-80 PSI. Lower air pressures may produce erratic operation.
2. If there is noise on the AC power applied to the electronics, the noise will be superimposed on the DC power supplied to the PFC.
Most of the time this will not be an issue. For the occasions where it is an issue, an AC line filter will solve the problem.
3. High amounts of ambient EMI may also cause erratic operation. Select an environment for your demonstration away from potential
sources of EMI, such as fluorescent lights, switching power supplies, power lines, and electric motors.
To ensure top performance in field applications, always ask your customers:
Is the air clean? Are you using filters and desiccant driers? Are there contaminants in the envi-ronment? The PFC is designed
to operate using clean, dry, non-lubricated air. Moisture, dirt, and lubri-cants, especially silicon, will shorten life when they work their way
inside the cylinder. Conductive inks silk screened onto the probe are eroded quickly when water or contaminants condense onto the
probe. In moist or dirty environments, filters and desiccant driers must be used, and failure in these applications is a result of improper air
prep, not defects in workmanship or materials.
Is your PCS control connected properly? Fittings should be air tight, not cracked or leaking, sealed with Teflon®tape. Avoid
small diameter air hoses; they reduce force. Avoid long lengths of hose between the PCS valve ports and the PFC; long lengths slow
response. All electrical connections, especially the control voltage to the PCS and the feedback signal from the PFC, must be shielded.
Inadequate shield-ing results in erratic response. The simplest way to ensure adequate shielding and circumvent EMI in-terference
problems is to order a PCS control with the Q option and companion shielded cables. Power supplied to the PCS should be clean.
Is your PCS control adjusted properly? Erratic operation is often caused by improper adjustment of the PCS control. For smoother
operation, increase the deadband and decel settings. If the control is set up under no load and a load is applied, the deadband and
decel may need to be increased. Trying to stop the load TOO SUDDENLY will result in overshoot, which will cause a correcting position
signal to be applied, which will cause overshoot, and so on. The piston will buzz for a while back and forth before settling into position.
The adjustments on the PCS circuit board are via multi-(many)-turn pots. The pots do no have hard stops, so they can be turned dozens
of times; users sometimes lose track of what they are doing, and keep turning them. To fix this problem, just follow the adjustment
procedure in the en-closed instructions.
Have you specified the low friction option? For accurate positioning, always specify the low friction option. If the customer complains
about rough operation and the cylinder being used is not low friction, a low friction option will help a lot.
What is your air pressure? At 70-80 psi, the PCS control and PFC cylinder operate normally. At low pressures, operation will be rough
and erratic.
Are you using flow controls? If flow controls are installed in the cylinder ports, erratic operation may result.
Technical Tips
PCS-PFC Quick Set-up Instructions
The information presented is in Bimba’s best engineering opinion and should be used for reference only. Recommendations derived should be verified under actual operating
conditions. Bimba reserves the right to change specifications without prior notice.
Bimba Manufacturing
Telephone: [phone]
Email: [email protected]
www.bimba.com
To learn more, scan this QR code
with your mobile device.
Leaders in Actuation.