Bimba PCS Rod Lock User Manual

Thanks for demonstrating the Bimba pneumatic positioning control products!

line filter will solve the problem

PCS

PFC

ldi

SUDDENLY will result in overshoot, which will cause a correcting position signal to be applied, which will

Use these instructions to demonstrate PFC operation, adjustment, set-up, and capabilities. The cylinder has a rod

lock; instructions are provided to demonstrate its operation. We have also included instructions for integrating
the rod lock into an application.

The demo unit has been fully tested, and is performing well. All components are new, made to the latest revision. The

PFC has a rod insulator, typical of our latest design.

If on occasion you should find that the demo is not operating as it should, consider the following:

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

.

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 environment? The

PFC is designed to operate using clean, dry, non-lubricated air. Enemies of the PFC are moisture, dirt, and
lubricants, especially silicon. 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

and the feedback signal from the
response. The simplest way to ensure adequate shielding and circumvent EMI interference 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

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 not 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 enclosed 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.

, must be shielded. Inadequate shie

ng results in erratic

Bimba Model PCS Pneumatic Control

Components required for a complete closed loop system:

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.

 PCS electro-pneumatic controller (includes valves).
 PFC, PFCN, PTF, or PTFN cylinder
 Air supply (70-80 psi required for proper operation.
 Regulated, filtered DC voltages.
 24 VDC fixed for PCS.
 0-10 VDC variable control voltage.
 120 VAC line power for DPM if used.
 DPM panel meter (for direct positioning readout)

Demo Case Circuit Diagram

Getting started

pply

pppy

valves (see image to the

3

Rod Lock L

Potentiometer

Switch

DPM

terminal blocks. They are

Power up and connect air su

to demo case.

Be sure rod lock lever is in “UNLOCK” position.

Observe the connection of
air lines to cylinders and

right). Valves are part of the
PCS control. The demo
contains a DC power supply,
switch, and potentiometer,
which would normally be
supplied in the application.
The multimeter should be in
VOLTAGE position. It ranges
from volts to millivolts; don’t
be confused by this: 1000
mV equals 1 V.

Positions 1 through 4 on the
rotary switch move the piston
in increments of one inch.
Position 5 switches to the
potentiometer, which moves
the piston continuously to
any position in its stroke.

Bar

Rod Lock

1
2

Rotary

ever

RST

Multimeter

The DPM is only used to
display displacement in
inches.

Remove cover to expose the
PCS control. Review all
positions in the top three

clearly marked. Electrical
connection to valves is not
required of customer for
encased controls. Identify trim
pots and LEDs, which are also
clearly labeled.