Det-Tronics R8471E User manual

Instructions 95-8410
Carbon Monoxide Controller
R8471E
2.1 8/07 95-8410

Table of Contents
Section I - General Information
DESCRIPTION................................................................................................1
FEATURES......................................................................................................1
SPECIFICATIONS...........................................................................................2
Controller ..................................................................................................2
Sensor.......................................................................................................2
SYSTEM OPERATION....................................................................................3
Sensor.......................................................................................................3
Controller ..................................................................................................3
Section II - System Installation
INSTALLATION ...............................................................................................9
Sensor Location........................................................................................9
General Wiring Requirements...................................................................9
Sensor Wiring .........................................................................................10
Controller Wiring.....................................................................................11
Controller Programming..........................................................................14
INSTALLATION CHECKLIST........................................................................15
Section III - System Startup
STARTUP PROCEDURE..............................................................................15
SETPOINTADJUSTMENT............................................................................16
Setpoint Display Mode............................................................................16
Setpoint Adjustment Procedure ..............................................................16
CALIBRATION...............................................................................................17
Calibration Procedure.............................................................................17
Current Output Calibration......................................................................18
Section IV - System Maintenance
ROUTINE MAINTENANCE...........................................................................18
Manual Check of Output Devices ...........................................................18
Checkout in Normal Mode ......................................................................18
Hydrophobic Filter...................................................................................18
SENSOR CELL REPLACEMENT..................................................................19
TROUBLESHOOTING ..................................................................................19
REPLACEMENT PARTS...............................................................................19
DEVICE REPAIR AND RETURN...................................................................21
ORDERING INFORMATION.........................................................................21

Section I
General Information
Carbon monoxide (CO) is a colorless, odorless gas
that is toxic to human life at low concentrations.
Figure 1 shows the effects of various concentrations
of CO on the human body.
DESCRIPTION
The R8471E is a single channel, rack mounted
controller that provides continuous monitoring of a
Det-Tronics electrochemical CO sensor or any other
CO sensor/transmitter assembly capable of generating
a 4 to 20 ma dc signal. Controller response includes
actuation of solid state or optional relay outputs for
direct control of field response devices, a full array
of faceplate indicators, as well as an optional 4 to 20
ma output for transmitting system information to other
devices. FEATURES
• Controller accepts a 4 to 20 ma input.
• Digital display, bar graph display and high intensity
LEDs indicate important system status information.
• AutoCal feature provides easy and accurate calibra-
tion.
• Microprocessor based controller is easily field pro-
grammable.
• Three independent alarm outputs with field select-
able setpoints.
• Base model is furnished with solid state alarm and
fault outputs.
• Premium model is furnished with relay outputs and a
4 to 20 ma dc output.
• Current output is selectable for isolated/non-isolated
operation.
• Available operating ranges are 0 to 100, 0 to 500
and 0 to 1000 ppm.
• Rack compatible with Det-Tronics R7400 series
flame controllers.
INSTRUCTIONS
Carbon Monoxide Controller
R8471E
2.1 ©Detector Electronics Corporation 2007 8/07 95-8410
CLEAN AIR
MAXIMUM PERMISSIBLE (8 HR)
HEADACHES
DIZZINESS
UNCONSCIOUSNESS
DEATH
NAUSEA
CEILING LEVEL
1000 PPM
600 PPM
200 PPM
50 PPM
0 PPM A1531
Figure 1—Effects of CO on the Human Body

95-84102.1 2
SPECIFICATIONS
CONTROLLER
OPERATING VOLTAGE—
24 vdc. Can operate in the range of 18 to 32 vdc.
POWER CONSUMPTION (controller only)—
Base model: 0.7 watt nominal, 1.3 watts maxi-
mum (25 ma nominal, 50 ma maxi-
mum at 24 vdc.)
Premium model: 1.2 watts nominal, 3.5 watts maxi-
mum (50 ma nominal, 145 ma
maximum at 24 vdc.)
Maximum startup current is 0.6 ampere for 10 milli-
seconds. Power supplies with fold back current limit-
ing are not recommended.
MAXIMUM RIPPLE—
Not to exceed 5 volts peak-to-peak.
TEMPERATURE RANGE—
Operating: +32°F to +140°F (0°C to +60°C)
Storage: –49°F to +185°F (–45°C to +85°C).
OPERATING RANGES (not programmable)—
0 to 100 ppm, 0 to 500 ppm, or 0 to 1000 ppm.
SOLID STATE OUTPUTS (Base model only)—
The outputs are open collector transistors with a 100K
resistor from the collector to emitter with the emitter
grounded, rated 100 ma at 32 volts dc maximum.
RELAY CONTACTS (Premium model only)—
SPST relays with selectable normally open/normally
closed contacts, rated 5 amperes at 30 vdc.
CURRENT OUTPUT (Premium model only)—
4 to 20 ma, with a maximum external loop resistance
of 600 ohms at 20 vdc and 1100 ohms at 32 vdc.
DIMENSIONS—
See Figure 2.
SHIPPING WEIGHT (approximate)—
2.0 pounds (0.9 kilogram).
SYSTEM APPROVAL—
The R8471E Controller, base and premium model in
3U and 4U height, has been tested and approved by
FMA. It can be used with any FMA approved sens-
ing device capable of generating a 4 to 20 ma input.
FMA approval of the R8471E Controller, however,
does not include or imply approval of input devices
such as sensors or transmitters, or devices connect-
ed to the controller outputs. To maintain FMA system
approval, all equipment connected to the controller
must be FMA approved.
NOTE
Ensure sensor hazardous (classified) location
rating is applicable for the intended use.
SENSOR
OPERATING RANGE (not programmable)—
0 to 100 ppm, 0 to 500 ppm, or 0 to 1000 ppm.
Sensor operating range must match that of controller.
TEMPERATURE RANGE—
+23°F to +105°F (–5°C to +40°C). Recommended
storage: +32°F to +68°F (0°C to +20°C).
TEMPERATURE RESPONSE—
Less than ±10% of gas concentration or ±3% full
scale, whichever is greater, from –5°C to +40°C.
HUMIDITY RANGE—
15 to 90% RH, non-condensing.
PRESSURE RANGE—
Ambient pressure ±10%.
ACCURACY—
±10 percent of applied gas concentration or ±3% full
scale, whichever is greater.
REPEATABILITY—
±2% of applied gas concentration or ±1% full scale,
whichever is greater.
RESPONSE TIME—
20 percent full range within 18 seconds, 50 percent
full range within 30 seconds when CO concentration
equal to full scale is applied.
➛
➛
9.3 (23.6)
1.0
(2.5)
7.0 *
(17.8)
➛
➛
➛
➛
A1526
* 4U DIMENSIONS SHOWN, 3U HEIGHT IS 5.2 (13.3)
Figure 2—Controller Dimensions in Inches (Centimeters)

95-8410
2.1 3
ENCLOSURE MATERIAL—
Aluminum.
DETECTOR RATINGS—
The C7066E is designed to meet FM and CSA require-
ments for Class I, Division 1, Groups C and D.
DIMENSIONS—
See Figures 3 and 4.
SHIPPING WEIGHT (Approximate) —
1.0 pound (0.5 kilogram).
WARRANTY—
Limited warranty 12 months on hardware, 24 months
on sensor cell.
SYSTEM OPERATION
SENSOR
The C7066E CO Sensor consists of an explosion-
proof aluminum housing with a field replaceable
electrochemical sensor cell. The transmitter circuitry
for generating a 4 to 20 ma output signal is contained
within the sensor housing, eliminating the need for a
separate transmitter.
The sensor is designed for use in Class I, Division 1,
Groups C and D hazardous locations.
The C7066E uses a hydrophobic filter to protect the
electrochemical sensor cell from contamination by
dirt and moisture. Unlike metal filters that significantly
restrict the passage of gases to the sensor cell when
the surface is coated with water, the hydrophobic filter
sheds water and will not inhibit the flow of CO gas to
the sensor cell. As with any filter, the hydrophobic
filter must be kept free of contaminants to allow CO
gas to reach the sensor cell.
The hydrophobic filter and electrochemical sensor cell
can be replaced quickly and conveniently in the field.
Sensor Cross Sensitivity
Table 1 shows the response of a typical
electrochemical CO sensor when exposed to various
commonly encountered substances.
CONTROLLER
Faceplate Description
The controller faceplate provides LEDs for identifying
system status conditions, a digital display and a
bar graph display for indicating the sensor input,
and pushbuttons for programming, calibrating and
resetting the system. See Figure 5 for the location of
indicators and pushbuttons.
1. Digital Display - The digital display provides a
continuous reading in parts per million (ppm) of
the sensor input in both the Normal and Calibrate
modes. In the event of a fault, it identifies the
nature of the fault using an alpha-numeric
code. In other operating modes it shows the
alarm setpoints and programmed calibration gas
concentration. A negative zero drift condition is
indicated by a minus (–) sign in the left hand digit.
Since this display is always on, it also functions
as a power indicator (except during the power-
up time delay, when the Fault LED is on and the
digital display is off).
A1527
5.0
(12.7)
3/4 INCH (20 MM)
STANDARD PIPE THREAD
1.1
(2.8)
2.2
(5.6)
3.77
(9.6)
1.28
(3.3)
3.46
(8.8)
4.7
(11.9)
2.7
(6.9)
5.2
(13.2)
5.86
(14.9)
B2281
Figure 4—Junction Box Dimensions in Inches (Centimeters)
Figure 3—C7066E Sensor Dimensions in Inches (Centimeters)
Gas Concentration Signal
Carbon Dioxide 25% 0
Chlorine 10 ppm 0
Ethylene 100 ppm <50
Hydrogen 100 ppm <60 ppm
Hydrogen Chloride 100 ppm 0
Hydrogen Cyanide 100 ppm 0
Hydrogen Sulfide 100 ppm <5 ppm
Methane 5% 0
Nitric Oxide 100 ppm <5 ppm
Nitrogen Dioxide 100 ppm <5 ppm
Sulfur Dioxide 100 ppm <5 ppm
Table 1—Cross Sensitivity of Electrochemical CO Sensor

95-84102.1 4
NOTE
In the event of an over-range condition, the
digital display flashes as long as the over-range
condition exists. The user must exercise caution
if an over-range reading is indicated, since a
dangerous condition could exist. The hazardous
area should be checked with a portable detection
instrument to determine the actual level of CO
gas present.
2. Bar Graph Display - The 20 segment bar graph
display provides a reading of sensor input.
3. High Alarm LED - Flashes in response to a sen-
sor signal that exceeds the high setpoint.
4. Auxiliary Alarm LED - Flashes in response to a
sensor signal that exceeds the auxiliary setpoint.
5. Low Alarm LED - Flashes in response to a sensor
signal that exceeds the low setpoint.
NOTE
Alarm LEDs flash when the setpoint is reached
and are on steady (until reset) when the CO
level drops below the setpoint, whether the
corresponding alarm output is latching or non-
latching.
6. CAL LED - Illuminated while the controller is in the
calibrate mode.
NOTE
In the Setpoint Display or Setpoint Adjust mode,
a flashing alarm LED identifies the particular
setpoint currently being indicated on the digital
display. A flashing CAL LED indicates that the
programmed calibration gas concentration in ppm
is currently being shown on the digital display.
7. FAULT LED - Flashes upon detection of a system
fault and is on steady during the power-up time
delay.
8. RESET Pushbutton - Used for various system
programming and calibration functions as well as
for resetting the controller.
9. SET Pushbutton - Used for various system pro-
gramming and calibration functions.
Operating Ranges
The R8471E is available in three operating ranges:
• 0 to 100 ppm
• 0 to 500 ppm
• 0 to 1000 ppm.
The operating range is not field programmable and
must be specified when ordering.
It is essential for the operating range of the sensor to
match the operating range of the controller to which
it is connected. Note that three sensor housings and
three electrochemical cells are offered. Be sure that
all equipment is compatible when installing the new
system and when replacing sensor cells. Refer to the
“Ordering Information” section.
Setpoints
The R8471E CO Controller has three independent
alarm outputs (low, high and auxiliary), with field
selectable setpoints.
The programmed calibration gas concentration in
ppm is also displayed and adjusted with the alarm
setpoints. This value must be equal to the ppm
concentration of the calibration mixture that is used
for the span adjustment.
Refer to Table 2 for a list of setpoint adjustment
ranges.
Alarm setpoints and calibration gas concentration
can be checked and/or changed using pushbuttons
95-84104
HIGH LED
DIGITAL DISPLAY
BAR GRAPH
CAL LED
FAULT LED
B1384
RESET
PUSHBUTTON
SET
PUSHBUTTON
LOW LED
AUXILIARY LED
Figure 5—Controller Front Panel

95-8410
2.1 5
located on the front panel of the controller. See
the “Set-point Adjustment” section for complete
information.
Outputs
The R8471E Controller is available in a Base version and
a Premium version. The differences between the two
models are the output configuration and programming
options.
BASE MODEL
The base controller is furnished with open collector
transistor outputs (rated 100 ma at 32 volts dc) for
the Low alarm, High alarm, Auxiliary alarm and Fault
circuits. The normally de-energized alarm outputs
are energized when their corresponding setpoints are
reached. The fault output is normally energized and
becomes de-energized upon detection of a system
fault.
The low alarm, auxiliary alarm and fault outputs are non-
latching. The high alarm output is latching.
PREMIUM MODEL
The premium model is furnished with a set of four relays
in place of the four solid state outputs. Relays have
SPST contacts rated 5 amperes at 30 vdc.
This model also includes a selectable isolated/non-
isolated 4 to 20 ma dc current output for transmitting
system information to other devices. The linear 4 to
20 ma output corresponds to CO levels from 0 ppm to
100% full scale (0 to 100, 0 to 500 or 0 to 1000 ppm,
depending on controller model). If a system fault is
detected, the output drops to less than 1.0 ma. The
current output can be calibrated in the field to ensure
maximum accuracy. Refer to the “Calibration” section.
PROGRAMMING OPTIONS (PREMIUM MODEL ONLY)
Each of the four relays is field selectable for either
normally open or normally closed contacts using jumper
plugs located on the printed circuit board inside the
controller. (See Table 3.)
The alarm relays are also switch programmable for either
normally energized or normally de-energized operation
(programmable as a group only, not individually). The
fault relay is normally energized.
The low and auxiliary alarm relays are programmable
for either latching or non-latching operation. The high
alarm relay is always latching and the Fault relay is
non-latching. Latching relays are reset using either the
Reset pushbutton on the front panel of the controller or
an external reset switch.
The 4 to 20 ma circuit is selectable for isolated or non-
isolated operation.
Automatic Diagnostics and Fault Identification
The microprocessor based controller features self-
testing circuitry that continuously checks for problems
that could prevent proper system response. When
power is applied, the microprocessor automatically tests
memory. In the Normal operating mode, it continuously
monitors the input signal from the sensor to ensure
proper functioning. In addition, a “watchdog” timer
is maintained to ensure that the program is running
correctly. If a fault should occur:
— The FAULT LED flashes.
— The digital display identifies the nature of the fault
using an alpha-numeric code. Refer to Table 4 for
an interpretation of the codes.
95-84105
Range Low Alarm High Alarm Auxiliary Alarm Calibration Gas
0 to 100 5 to 50 10 to 90 5 to 90 30 to 90
Default 10 20 20 50
0 to 500 25 to 250 50 to 450 25 to 450 150 to 450
Default 50 100 100 250
0 to 1000 50 to 500 100 to 900 50 to 900 300 to 900
Default 100 200 200 500
Table 3—Selectable Relay Options
Relay Selectable Selectable Selectable
Normally Normally Latch/
Open/Closed Energized/ Non-Latch
De-Energized
Low Y Y1Y
1
High Y Y1N
2
Auxiliary Y Y1Y
1
Fault Y N3N
4
Y = Yes N = No
1Selectable as a group, not individually 2Latching only
3Normally energized only 4No latching option
Table 2—Setpoint Adjustment Ranges in PPM

95-84102.1 6
— The normally energized Fault output is de-ener-
gized.
— The dc current output drops to less than 1.0 ma.
NOTE
The fault code will be shown for about 2 seconds
out of every 5 seconds. The gas concentration at
the sensor will be displayed during the remaining
time. If more than one fault should occur, the
highest priority fault will be displayed. (Table 4
lists the faults in order of priority.)
An alarm condition will normally over-ride a fault
condition unless the fault condition occurred first. F10
and F2X will not over-ride an alarm. Faults that affect
the actual function of the controller (F50, F60, F70, F9X)
can impair the ability of the controller to maintain an
alarm output.
All faults automatically reset except the F9X, F20 and
F10 faults. After the fault condition has been corrected,
the fault output automatically switches to the normal
(energized) state, the dc current output returns to
normal, and the FAULT LED turns off. Clearing F9X
faults requires removing operating power from the
controller for approximately one second.
CAUTION
The fault detection circuitry does not monitor the
operation of external response equipment or the
wiring to these devices. It is important that these
devices be checked periodically to ensure that
they are operational.
Operating Modes
NOTE
The following section is intended to acquaint the
operator with the basic operation of the controller.
For complete step-by-step programming and
calibration procedures, refer to corresponding
sections in this manual.
The controller can operate in any of the following modes.
Operating modes other than Normal are selected by
pressing the appropriate pushbutton(s) located on the
controller front panel. See Figure 6.
POWER-UP TIME DELAY
When power is applied to the controller, it enters a
time delay mode to allow the sensor output to stabilize
before beginning normal operation. During this time
the outputs are inhibited, the FAULT LED is illuminated
and the current output indicates a fault condition (less
than 1.0 ma). At the end of the time delay, the controller
automatically enters the Normal operating mode.
NORMAL
In Normal operating mode with no alarm condition:
— Digital display is on and indicates the sensor input
in ppm.
95-84106
Table 4—System Status Codes
Status Condition
F9X Initialization failure. (Subcodes are as fol-
lows.)
F91 EPROM sumcheck failure.
F92 Sensor failure during startup - current too
high or too low.
F93 Watchdog timer failure.
F94 RAM failure.
F95 Internal 5 volt power supply failure during
startup.
F96 External 24 volt power supply failure dur-
ing startup.
F97 Controller type invalid. Error in data from
RAM.
F98 Watchdog timer reset the controller.
F70 External reset button has been activated
for 15 seconds or longer. Self clearing
when button is released.
F60 External 24 vdc power input is not in the
18 to 32 vdc range.
F50 Internal 5 volt power supply is not in the
4.75 to 5.25 volt range.
F40 Sensor fault (after startup). Input is above
35 ma or below 2 ma.
F30 Negative zero drift. Sensor input is –9%
full scale or lower.
F2X Calibration error. (Subcodes are as fol-
lows.)
F20 General calibration fault, or calibration
aborted due to a higher priority fault.
F21 Time ran out while waiting for calibration
gas to be applied to the sensor.
F22 Sensor input is too low. The sensor cannot
generate enough offset to get an accurate
calibration. Replace sensor.
F23 Sensor is too sensitive for the controller to
read 100% full scale. Replace sensor.
F24 Zero gas level too high, or sensor zero
input over limit.
F10 Sensor reaching end of life. Consider
replacing the sensor within the next two
calibration periods.

95-8410
2.1 7
— Bar graph display reads the same as the digital
display.
— All LEDs are off.
— Alarm outputs are in their normal state (energized
or de-energized as programmed).
— 4 to 20 ma signal level corresponds to sensor
input.
— Fault output is energized.
In the Normal operating mode with a low and/or auxil-
iary alarm condition occurring:
— Digital display and bar graph display indicate the
sensor input in ppm.
— Low and/or Auxiliary LED flashes.
— Low and/or Auxiliary alarm output changes state.
— 4 to 20 ma signal level corresponds to sensor
input.
— Fault output energized and LED off.
When the signal decreases below the low or auxiliary
setpoint:
— Digital display, bar graph display and 4 to 20 ma
output continue to track the sensor input.
— With latching operation programmed: No change
to alarm outputs.
— With non-latching operation programmed: Alarm
outputs return to their normal state.
— Low and Auxiliary LEDs are on steady until reset.
In the Normal operating mode and a high alarm con-
dition occurring:
— Same as a low or auxiliary alarm condition, but
High LED and high alarm output are affected.
When the signal decreases below the high alarm set-
point:
— The high alarm is always latching and unaffected
by the latching/non-latching programming for the
low and auxiliary alarms. High LED is on steady
until reset.
In the event of a system fault:
— The normally energized Fault output is de-ener-
gized and the FAULT LED is illuminated.
— 4 to 20 ma output drops to less than 1.0 ma.
RESET
The Reset mode is entered by pressing the RESET
button located on the front panel of the controller.
(See Figure 6.) When the RESET button is momen-
tarily depressed, all LEDs turn off and all outputs
return to their normal condition if no alarms or faults
are occurring (basic reset). When the RESET button
is held for 0.5 second, the LEDs turn off and the out-
puts return to their normal condition even if an alarm
or fault condition still exists (forced reset). Remote
95-84107
POWER-UP
POWER-UP
DELAY
NORMAL RESET
< 0.5 SEC. 1.0 SEC.
HOLD RESET
7 SEC.
SET
1.0 SEC. NO
YES
0.5 SEC 9.0 SEC.
BASIC
RESET FORCED RESET
RELEASE
RESET
RELEASE
RESET
RELEASE
RESET
SETPOINT
DISPLAY
HOLD
RESET
HOLD
RESET
HOLD
RESET
SENSOR
REPLACE
SETPOINT
ADJUST
CURRENT
CALIBRATE
RESET
PUSHED WITH
SET?
CALIBRATE
SET*
RESET
*MUST BE PRESSED BEFORE THE ZERO
CALCULATIONS ARE COMPLETED.
C1385
Figure 6—R8471E Controller Flow Chart

95-84102.1 8
reset capability is also provided. (Remote reset per-
forms a forced reset.)
NOTE
The remote reset performs a reset function only.
It cannot be used for entering other controller
operating modes.
SETPOINT DISPLAY MODE
If the RESET button is held for approximately one
second, the controller enters the Setpoint Display
mode. In this mode, the digital display sequentially
shows the programmed alarm setpoints and
calibration gas concentration. Each value is displayed
for approximately 2 seconds. After completing the
sequence, the controller automatically returns to the
Normal operating mode if the RESET button is no longer
being depressed.
This mode is used only for displaying the setpoints. Use
the “Setpoint Adjust” mode for changing setpoint and
calibration gas values.
CALIBRATE
The R8471E uses a fully automatic calibration procedure
that requires no adjustments by the operator. The
Calibrate mode is entered by pressing and holding the
RESET button until completion of the “Setpoint Display”
sequence described above (approximately 9 seconds).
The controller performs the Zero adjustments, then
signals the operator when to apply and also when
to remove the calibration gas. Upon completion of
a successful calibration, the controller automatically
returns to the Normal operating mode.
If the operator fails to complete the calibration
procedure, if an error in calibrating occurs, or if a
successful calibration cannot be completed, the
microprocessor will automatically return to the Normal
mode and continue to use the previous calibration data
(after 10 minutes or when the gas level drops below the
lowest setpoint). A fault indication (“F2X” status) will be
displayed until a reset occurs. If the microprocessor
determines that the sensor cell is approaching the end
of its useful life, “F10” will be indicated on the digital
display.
See “Calibration” section for complete information.
While in the Calibrate mode, all controller outputs are
inhibited, the CAL LED is illuminated and the dc current
output goes to a preset level (adjustable from 0 to 20
ma, with a default value of 4.0 ma).
SENSOR REPLACEMENT
This mode inhibits all controller outputs to allow
replacement of the sensor cell without removing power
from the controller. In addition, this mode automatically
sets the factory default values for sensor calibration.
Alarm setpoints and calibration gas concentration are
not affected.
CAUTION
Upon entering the Sensor Replacement mode, all
previously entered sensor calibration information
is lost. Sensor calibration must be performed,
even if the sensor cell was not replaced.
To enter the Sensor Replacement mode, either enter the
Calibrate mode as described above and press the SET
button, or hold the RESET button for 7 seconds while in
the power-up time delay. To exit this mode, press the
RESET button. Upon exiting the Sensor Replacement
mode, the controller automatically returns to normal
operation.
SETPOINTADJUST
The Setpoint Adjust mode is entered by depressing
the SET button for approximately one second. In this
mode the alarm setpoints and calibration gas level
are sequentially displayed on the digital display for
approximately five seconds and the corresponding LED
flashes. To change the setpoint, depress the RESET
button to increase the displayed value or the SET button
to decrease the value. If no changes are made for 5
seconds, the microprocessor automatically advances
to the next setpoint. At the end of the sequence, the
microprocessor automatically returns to the Normal
operating mode.
DC CURRENT OUTPUT CALIBRATION
This mode is used to calibrate the 4 to 20 ma dc
output. To enter this mode, hold the SET button, then
press RESET. Initially, a 4 ma output is generated
for approximately 7 seconds while the Low LED
flashes. Then 20 ma is generated while the High
LED flashes. Finally the current output level during
calibration is generated while the CAL LED flashes.
The microprocessor automatically returns to the
normal operating mode at the end of the sequence.
Adjustments to the current output level are made by
pressing the RESET (increase) or SET (decrease)
button. This procedure requires a dc current meter to
monitor the actual controller dc milliampere output.
95-84108