MONARCH INSTRUMENT ACT-3X User manual

ACT-3X
Tachometer / Totalizer / Ratemeter
User Manual and Reference Guide
MONARCH INSTRUMENT
15 Columbia Drive Amherst, NH 03031 USA
Phone: [phone] Fax: [phone]
E-mail: [e-mail]
Website: www.monarchinstrument.com

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Safeguards and Precautions
1. Read and follow all instructions in this manual carefully, and retain this manual for future
reference.
2. Do not use this instrument in any manner inconsistent with these operating instructions or
under any conditions that exceed the environmental specifications stated.
3. Be sure the power supplied to this instrument matches the specification indicated on the rear
panel of the instrument
4. Be sure all power is removed before making or removing any connections to or from this
instrument.
5. There are no user serviceable parts in this instrument. Refer service to a qualified technician.
6. Do not allow cables extending from unit to come into contact with rotating machinery, as
serious damage to the equipment, or severe personal injury or death may occur as a result
7. This instrument may not be safe for use in certain hazardous environments, and serious
personal injury or death could occur as a result of improper use. Please refer to your facility’s
safety program for proper precautions.
In order to comply with EU Directive 2012/19/EU on Waste Electrical and Electronic
Equipment (WEEE): This product may contain material which could be hazardous to human
health and the environment. DO NOT DISPOSE of this product as unsorted municipal waste.
This product needs to be RECYCLED in accordance with local regulations, contact your local
authorities for more information. This product may be returnable to your distributor for
recycling - contact the distributor for details.
Monarch Instrument’s Limited Warranty applies.
See www.monarchinstrument.com for details.
Warranty Registration and Extended Warranty coverage available online at
www.monarchinstrument.com.
Rev 1.2, June 2019

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T
TA AB BL LE E O OF F C CO ON NT TE EN NT TS S
1.0 GENERAL OVERVIEW..............................................................................1
2.0 INSTALLATION .........................................................................................1
2.1 Noisy Environments ......................................................................................................... 1
2.2 Adjustments ...................................................................................................................... 2
2.3 Connections ...................................................................................................................... 2
2.3.1 Power Connections.............................................................................................. 2
2.3.2 Sensor Connections ............................................................................................ 2
2.3.3 Analog Output ...................................................................................................... 3
2.3.4 Auxiliary Input (AUX- Channel 2)........................................................................ 3
2.3.5 Pulse Output......................................................................................................... 3
2.3.6 Alarm Relay Outputs............................................................................................ 3
2.3.7 Serial Communications ....................................................................................... 4
3.0 FRONT PANEL ..........................................................................................4
3.1 Status LED’s ...................................................................................................................... 4
3.1.1 LIM 1 and LIM 2 (Alarm) LED’s ........................................................................... 4
3.1.2 GATE LED ............................................................................................................. 4
3.1.3 MAX and MIN LEDS.............................................................................................. 4
3.1.4 RPM LED ............................................................................................................... 4
3.2 Push Buttons..................................................................................................................... 4
3.2.1 SET BUTTON ........................................................................................................ 4
3.2.2 RESET BUTTON ................................................................................................... 4
3.2.3 UP () and DOWN () BUTTONS......................................................................... 5
3.2.4 RECALL BUTTON................................................................................................. 5
4.0 OPERATION ..............................................................................................5
4.1 Modes of Operation –Channel 1 ..................................................................................... 5
4.1.1 RPM Mode............................................................................................................. 5
4.1.2 Frequency Mode................................................................................................... 5
4.1.3 Scale Mode (Ratemeter) ...................................................................................... 5
4.1.4 Single Event Capture (SECAP) Mode................................................................. 5
4.1.5 Rate of Change (ROC) Mode............................................................................... 5
4.1.6 Totalizing Mode .................................................................................................... 6
4.2 Modes of Operation –Channel 2 ..................................................................................... 6
4.2.1 Off .......................................................................................................................... 6
4.2.2 Inhibit .................................................................................................................... 6
4.2.3 Single Event Capture ........................................................................................... 6
4.2.4 External Reset –Input Totalizer ......................................................................... 6
4.2.5 External Reset –Alarms...................................................................................... 6
4.3 Decimal Point .................................................................................................................... 6
4.4 Alarm Limits ...................................................................................................................... 6
4.4.1 Latching vs. Non-Latching Limits ...................................................................... 7
4.4.2 Dead band (Hysteresis) ....................................................................................... 7
4.4.3 Low Limit Lockout ............................................................................................... 7
4.4.4 Fail Safe ................................................................................................................ 7
4.5 Analog (AO) and Current (IO) Output.............................................................................. 7
4.6 Maximum and Minimum ................................................................................................... 7
4.7 Throughput ........................................................................................................................ 8
4.7.1 Display Update Rate ............................................................................................ 8
4.7.2 Internal Update Rate - GATE............................................................................... 8
4.7.3 Low End ................................................................................................................ 8

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4.8 PULSE OUTPUT ................................................................................................................ 8
5.0 USING THE MENU ....................................................................................8
5.1 ..................................................................................................................................... 9
5.1.1 ........................................................................................................................ 9
5.1.2 ...................................................................................................................... 9
5.1.3 ...................................................................................................................... 9
5.1.4 ...................................................................................................................... 9
5.1.5 ...................................................................................................................... 10
5.2 ................................................................................................................................... 10
5.2.1 ...................................................................................................................... 10
5.2.2 .................................................................................................................... 10
5.3  ............................................................................................................................... 10
5.4 ................................................................................................................................. 10
5.4.1 .................................................................................................................... 10
5.4.2 .................................................................................................................... 10
5.4.3 ........................................................................................................................ 10
5.4.4 .................................................................................................................... 11
5.4.5 .................................................................................................................... 11
5.4.6 .................................................................................................................... 11
5.5 ................................................................................................................................. 11
5.6 ................................................................................................................................. 11
5.6.1 .................................................................................................................... 11
5.6.2 .................................................................................................................... 11
5.6.3 ...................................................................................................................... 11
5.7 ................................................................................................................................... 11
5.8 ................................................................................................................................... 11
5.9  ............................................................................................................................... 11
5.10  ................................................................................................................................. 11
5.11 ................................................................................................................................. 12
5.12 ................................................................................................................................. 12
6.0 SERIAL OUTPUT.....................................................................................12
6.1 Data from the Serial Interface ........................................................................................ 12
6.2 Serial Commands............................................................................................................ 12
6.2.1 Run Mode Commands ....................................................................................... 12
6.2.2 Control Commands............................................................................................ 13
7.0 SPECIFICATIONS ...................................................................................14
8.0 OPTIONS AND ACCESSORIES / SENSORS .........................................15
APPENDIX A –SCALING THE ACT FOR ENGINEERING DISPLAYS ............16
APPENDIX B –USEFUL CONVERSIONS.........................................................17
APPENDIX C –USING THE SINGLE EVENT CAPTURE MODE......................18
APPENDIX D –SETTING UP THE ETHERNET INTERFACE ...........................19
APPENDIX E –MENU OVERVIEW....................................................................20

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1.0 GENERAL OVERVIEW
The ACT-3X digital panel meter is an extremely versatile instrument. The user has complete control of the unit configuration.
Power may be either 115 - 230 Vac (50/60 Hz), or optionally, 12 Vdc or 24 Vdc. Input signals are accepted (on Channel 1) from
optical, proximity, magnetic, infrared or laser sensors, or direct TTL or external AC sources. A second AUXiliary input
(Channel 2) may be used for instrument control and remote resetting. There are several remote communication options –RS232,
USB or Ethernet and the optional remote software can be used to program the unit or display data locally. The unit is suitable for
panel mounting or bench top use, with convenient screw terminal connections on the rear panel of the instrument.
When the instrument is turned on, it displays all 8s, then ―3 rx.x‖, where 3 is the unit type (ACT3) and rx.x is the software
revision level, before entering the normal mode of operation.
The display will show ―- - - - -‖ when a measurement is over range.
2.0 INSTALLATION
The instrument is intended to operate in the following environment: Indoor Use Only
Installation Category II per IEC 664 Pollution Degree Level II per IEC61010-1
Measurement Category I per IEC61010-1 Altitude up to 2,000 m
Temperature -10 °C to +50 °C operating per IEC61010-1
Humidity Maximum relative humidity 80% for temperatures up to 31°C decreasing linearly to 50%
relative humidity at 40°C
AC Mains Supply 100 - 240 Vac ~ +10% 50/60 Hz 8 VA
DC Supply (Option) 12 or 24 VDC+10% 6 watts (DC Option)
NOTE: The instrument is designed to be panel mounted and as such should be considered as fixed
equipment or permanently connected. If permanently connected, disconnection from the supply
must be possible via a customer supplied switch or circuit breaker rated at 120V or 240V
(dependent on local voltage supply) 5A minimum when connected to an AC supply or 30V 1A
minimum when connected to a DC supply. This disconnection device must disconnect all current-
carrying conductors. It must be included in the panel installation and should be clearly marked, in
close proximity to the Unit and easily accessible to the operator.
The ACT3X is a 1/8 DIN enclosure requiring a 3.58‖ wide by 1.74‖ high (91x44 mm) mounting hole. Approximately 5‖ (127
mm) will be required behind the panel. Refer to Figure 1 below.
Before installing, check the power
supply requirements on the rear
panel. Remove the mounting clips,
if fitted, and install the unit into the
panel from the front. From the rear
of the unit, install the mounting
clips into the slots on each side of
the unit and tighten the mounting
screws against the front panel.
WARNING: Do not over
tighten the mounting screws.
Figure 1 Dimensions in Inches [Millimeters]
WARNING: Do not use this instrument in any manner inconsistent with these
operating instructions or under any conditions that exceed the
environmental specifications stated.
2.1 Noisy Environments
These instruments are highly responsive. They have input ranges up to 999,990 RPM and 250,000 Hz. They therefore have
extremely fast input circuitry that may respond to spurious noise. It is important to provide a clean source of power to the
units, either AC or DC, and to ensure that the input to the unit is free of spikes or any other high frequency noise. In noisy
environments, it may be necessary to supply power through a filter, or alternate source. The inputs may also need to be

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damped, to suppress high frequency noise. It is always a good idea to use shielded cable for input signals and ensure the
shield is properly grounded.
NOTE: The common on the inputs is NOTa ground.
Another source of noise is spikes generated by the alarm relay contacts. It may be necessary to suppress the contacts
externally. This is particularly true when the internal relays switch other external relays that do not have spike suppression.
Always ensure that all sources of spikes or noise are adequately suppressed from the environment.
2.2 Adjustments
Since the instruments are crystal controlled, there are no user calibration adjustments. Any of the programmable parameters,
such as scaling, limits, analog out, and so on must be set up using the menu options.
2.3 Connections
All connections are via the rear panel of the instrument –power, sensors, alarms, analog output, and communication. The
rear panel is shown below and may vary slightly depending on what options are in the unit.
Figure 2 ACT-3X Rear panel with Analog Output and USB Option
2.3.1 Power Connections
Power to the unit is connected to the terminals under the sections labeled POWER on the rear panel. Be sure the
power supplied matches the specification indicated on the rear panel. Refer to Figure 2 above.
If the unit is ac powered (115 - 230 Vac), connect the Live (Hot) wire to the terminal marked L and the Neutral
(Return) wire to the terminal marked N. NOTE: The ground connection is not required as the unit is fully isolated
from the mains.
If the unit is dc powered, connect the dc supply Positive to the terminal marked ―+‖ and the dc supply Negative or
Common to the terminal marked ―-‖. CAUTION: Ensure the dc voltage does not exceed the rating on the unit (12V
±10% or 24V ±10% as marked).
2.3.2 Sensor Connections
A speed sensor (not included) can be connected to the terminals under the section labeled IN on the rear panel. Refer
to Figures 2and 3.
Connections and their functions are as follows:
+V(A) Positive Supply Output. Used to provide power to optical, laser, infrared or amplified magnetic sensors.
Voltage out is +24Vdc, +12Vdc or +5Vdc (factory selected). Maximum load is 30mA from the 24V supply
or 60mA from the 5 or 12V supplies.
PX+ This output is for use with two wire proximity sensors. It has internal current sensing. Maximum load for
proper operation with two wire sensors is 20 mA.
SIG Signal Input. Positive input signal from the speed sensor. Accepts TTL pulses or ac signals, unipolar and
bipolar, from 1.1 Vac to 50 Vac. Connect the signal wire from three wire sensors or the positive side of two
wire magnetic sensors to this terminal. Typical input impedance is 10 Kohms.
COM Common or Negative Terminal. Common or Negative connection for both signal and power.
Refer to Figure 3 on the following page for connection of Monarch standard sensors. The connections are typical for
these types of sensors.

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Figure 3 Sensor Connections
2.3.3 Analog Output
The Analog Output is an option. The Output option is marked on the back of the unit to the right of the connector –
refer to Figure 2.
2.3.3.1 Current Output
The current output is 4 to 20 mA. This output is a current source and has a 12 Volt
dc internal compliance voltage. (Optional 24 Vdc may be ordered).
Typical connection is as follows: (See Figure 4.)
Connect the Positive side of the load to the OUT terminal marked ―+‖ and the other
side of the load to the terminal marked ―-―. With the internal 12 Vdc compliance
voltage the maximum load for the current loop is 500 Ohms. If the optional 24 Vdc
compliance option is ordered the maximum load will be 1000 Ohms.
2.3.3.2 Voltage Output
The analog output is 0 to 5 Vdc @ 5mA.
Connect the Positive side of the load to the OUT terminal marked ―+‖ and the return
side of the load to the terminal marked ―-‖. (See Figure 4.)
The output full scale and zero scale values are programmed via the front panel or remotely through the communication
port.
2.3.4 Auxiliary Input (AUX- Channel 2)
The Auxiliary Input is also referred to as Channel 2 (CH-2) and will accept a TTL input or any signal up
to 12Vdc. It has a weak pull up internally and can be used with a set of potential free contacts. The AUX
input is programmed via the front panel or remotely via the communication port. Refer to Figure 2 and
figure shown right –the AUX input is connected to the input marked AUX (+) and COM (-).
2.3.5 Pulse Output
The Pulse Output provides a pulse out for each pulse in. It is a TTL pulse switching between +5V and
ground. Refer to Figure 2 and figure shown right - the connection is to the PO (+) terminal and the COM
(-) terminal.
2.3.6 Alarm Relay Outputs
The Alarm Relay Outputs are potential free Form C contacts (Change Over) capable of
carrying 1A at 250Vac or 30Vdc.
The contacts are marked NCx where NC is the Normally Closed Contact, x = 1 or 2
depending on which relay you are using. CM is the Common and NO is the Normally Open Contact.
CAUTION: Relay contacts may be wired to external high voltage potentials –ensure all power to the contacts is off
before attempting any wiring.
CAUTION: During programming of the device, relay contacts may make or drop out intermittently.
Figure 4 Analog
Output Connections
+ OUT -
NOTE: Sensor shields may be attached to
input common (COM) if a ground point is
not available.

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2.3.7 Serial Communications
There are three serial communication options –Ethernet, USB and RS232. The Ethernet option will have a standard
RJ45 connector, the USB option will have a type B female connector, and the RS232 option will have a male DB9
connector on the rear panel. The connections of the Ethernet and USB are generic. For information on setting up the
Ethernet Interface refer to Appendix D. The connection of the RS232 DB9 is shown here:
Pin Description Direction
2 Receive data In
3 Transmit Data Out
5 Common (GND)
7 Request to Send RTS Out
8 Clear to Send CTS In
All other pins are not used. Communications are at the preset Baud Rate, 8 bits, No Parity and 1 stop bit.
3.0 FRONT PANEL
Refer to the first page for a photo of the front panel.
The front panel of the instrument has 5 push buttons, five 0.56‖ 7 segment light emitting displays, and six single light emitting
diodes (LED’s), marked LIM 1, LIM 2, GATE, MIN, MAX and RPM. Some of these LED’s may not be visible; it depends on
the mode the unit is in.
3.1 Status LED’s
3.1.1 LIM 1 and LIM 2 (Alarm) LED’s
The LIM 1 and LIM 2 (Alarm) LED’s indicate the status of the limits, particularly of the alarm output relay. When an
alarm trips, the corresponding LED blinks at a rate around 1 flash per second. When the alarm resets, the LED goes
out. These LED’s also go on continuously to indicate when and which limit is being set or adjusted. If the LED’s are
on continuously, the value on the display is a set point value, not the input value.
3.1.2 GATE LED
The GATE LED is an indication of the instrument’s input trigger signal from a sensor. It is triggered on by the falling
edge of an input pulse, and goes off about 150 milliseconds later (unless there is another input pulse). It is more useful
at slow speeds, as it appears to be on continuously at higher inputs. It gives an indication that a valid input trigger
signal is present.
3.1.3 MAX and MIN LEDS
The MAX and MIN LED’s indicate to the user that a maximum or a minimum is being displayed. If either one of
these LED’s is on, the display is a stored value, not the input value.
3.1.4 RPM LED
The RPM LED indicates that the RPM Mode (frequency x 60) has been selected, which can only be used when the
input is one pulse per revolution. The RPM LED is off in all other modes. In the Scale Mode the read outs may be in
RPM, but the RPM LED will be off.
NOTE: For applications where there is more than one pulse per revolution, the Scale Mode must be used.
3.2 Push Buttons
The five push buttons on the front panel have multiple functions. The following sections cover the function of the buttons
under normal operating conditions.
3.2.1 SET BUTTON
The SET button enters the Menu and allows the user to view the current settings in the unit. Refer to Section 5.0.
3.2.2 RESET BUTTON
The RESET button, when pressed, resets the Alarms, assuming they have tripped. It is the only way to reset a latching
alarm other than via the serial interface.
NOTE: If an alarm set point is exceeded when the reset button is pressed, the alarm will immediately trip again on
the next data acquisition cycle.
If the user holds the RECALL button and then presses the RESET button, the minimum and maximum values (and the
TOTAL if the unit is in the Totalizing mode) are reset.
In the Single Event Capture (SECAP) Mode, pressing the RESET button signals the instrument to take a reading at the
next trigger as well as its normal functions.
When in the Menu, the RESET button reverts back one level without saving any changes () or exits the Menu
(). However, when entering data values in the menu such as scale factor, set point, Ethernet settings or passcode,

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the RESET button changes the digit being edited (blinking digit). Also when entering a data value, holding down the
RESET button and pressing the DOWN ()button will move the decimal place.
3.2.3 UP () and DOWN () BUTTONS
The UP  and DOWN  buttons can be used to view the current settings of the alarms. Press the UP  button to
view LIMIT 1 or the DOWN  button to view LIMIT 2. The display will revert back to normal after a few seconds.
When in the Menu, the UP  and DOWN  buttons are used to scroll through the menu options or edit data within
the options.
3.2.4 RECALL BUTTON
The RECALL button toggles between the maximum and minimum readings. The display will revert back to normal
after a few seconds. The RECALL button, when used with the RESET button, also resets the maximum and minimum
readings or total (when in Totalizing mode).
When in the Menu, the RECALL button reverts back one level without saving any changes () or exits the Menu
().
4.0 OPERATION
4.1 Modes of Operation –Channel 1
There are a number of different modes of operation. These modes determine what is shown on the display for any given
input to the instrument. Basically, it determines what computation is performed on the input. The input signals are on
Channel 1 (Signal inputs). The user can set the sense of the input, positive or negative. The AUXiliary input (Channel 2) can
be used to control the signals on Channel 1. Refer to Section 5.0 for details on changing modes.
NOTE: The instrument is programmed from the factory in the RPM Mode for one pulse per revolution.
4.1.1 RPM Mode
In the RPM Mode the unit behaves like a tachometer displaying revolutions (revs) per minute (RPM) from an input of
1 pulse per revolution. The instrument effectively multiplies the input frequency (pulses per second) by sixty to derive
RPM. In this mode, the range of the unit is 5 to 999,990 RPM. The RPM LED on the bottom right of the display area
illuminates to indicate the RPM mode is programmed. The AUXiliary input (Channel 2) can be used to inhibit (disable)
the signal into the unit.
NOTE: For applications with more than one pulse per revolution, the Scale Mode (see below) must be used to
display RPM or other rates.
4.1.2 Frequency Mode
In the Frequency Mode, the unit displays input pulses per second or more commonly, Hertz (Hz). This is the most
basic mode of operation. The range of measurement in this mode is 0.0833 to 250,000 Hz. The AUXiliary input
(Channel 2) can be used to inhibit (disable) the signal into the unit
4.1.3 Scale Mode (Ratemeter)
In the Scale Mode of operation, the input frequency (pulses per second) is multiplied by a constant, which is set by the
user, and displayed. This allows the user to scale the input to obtain a read out in any units required: RPM, inches per
second, meters per hour, yards per fortnight, and so on. The scale factor may be set anywhere from 0.0001 to 99,999.
The AUXiliary input (Channel 2) can be used to inhibit (disable) the signal into the unit.
4.1.4 Single Event Capture (SECAP) Mode
The SECAP (Single Event Capture) Mode is just like the Scale Mode except that only one reading is made. The
RESET button is pressed to start each new measurement. The unit will then use the next input pulse to start a
measurement, then the next input pulse will end the measurement. In the other tachometer modes, the unit will keep
acquiring pulses until 10 mS (STD gate) or 1 mS (FAST gate) has passed so it can give an accurate reading. The
SECAP Mode sacrifices accuracy as measurements get shorter than 32 mS (STD gate) or 4mS (FAST gate), but it is
the only way to measure single (non-repeating) events. The AUXiliary input may be used for the second pulse input if
two sensors are used, the first pulse on Channel 1 will start the process and the second pulse on Channel 2 (AUX) will
stop the process. Refer to Appendix C - Using the Single Event Capture Mode.
4.1.5 Rate of Change (ROC) Mode
In the Rate of Change Mode, the unit displays the rate of change of the input frequency (pulses per second). The unit
measures the input frequency times the scale factor set by the user. A moment later it measures the input frequency
again. The difference of these two, scaled frequencies is divided by the time interval between the two measurements.
Several measurements are averaged then displayed.
The scale factor allows the user to scale the input to obtain a read out in any units required: RPM per Minute
(RPMPM), inches per second per second, meters per hour per minute, yards per fortnight per second, and so on. The
scale factor may be set anywhere from 0.0001 to 99,999.

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In this mode:
The display is updated up to once every two seconds with the average Rate of Change.
The throughput of the max/min, analog outputs, and relays is up to twice a second.
The display will show a positive number when the frequency is increasing and a negative number when the
frequency is decreasing.
Remember that even a small change in RPM over a short time will cause a large Rate of Change (average acceleration)
to be displayed. The gate time for each measurement is about 1/3 of a second. For instance, if you use a digital
function generator to change from 3000 RPM to 3001 RPM, the change will happen all at once. You will see that it
happens within 1/3 of a second. So 1 RPM change in 1/3 of a second is 180 RPM over one minute or 180 PRMPM
acceleration.
4.1.6 Totalizing Mode
In the Totalizing Mode, each input pulse causes the display to be incremented by a constant value that is set by the
user. This enables the user to scale the input to obtain a read out in any measure required: number of inches, number of
bottles, number of revolutions, and so on. The scale factor may be set anywhere from 0.0001 to 99,999. The total can
be reset using the RESET and RECALL buttons pressed together on the front panel. The AUX input (Channel 2) can
be set to reset the totalizer and turn the unit into a batch counter or to inhibit the input signal (see Section 4.2.4).
4.2 Modes of Operation –Channel 2
Channel 2 is the AUXiliary input and is basically used to control the input to Channel 1, or can be used as an external reset
for the input channel or the Alarms. The user can set the sense of the input, positive or negative. The input has a weak pull-
up resistor internally so it can be used with a potential free contact. All modes are mutually exclusive –only one mode may
be active at any time. Refer to Section 5.0 for details on changing modes.
NOTE: The instrument is programmed from the factory with the AUXiliary input disabled (OFF).
4.2.1 Off
When programmed OFF this input has no effect.
4.2.2 Inhibit
If programmed as an inhibit pin, it will disable the signal input when asserted (high or low depending on the sense
programmed). It acts as a gate preventing the input signal from updating the unit.
4.2.3 Single Event Capture
When programmed as Single Event Capture () this input acts as the second input for the external signal –see
Section 4.1.4 above.
4.2.4 External Reset –Input Totalizer
If programmed as External Reset for Inputs (), when asserted (high or low depending on the sense programmed),
it will reset the display (count) to Zero. Used in the Totalizer Mode (see Section 4.1.6) to enable the unit as a batch
counter.
4.2.5 External Reset –Alarms
If programmed as External Reset for Alarms (), when asserted (high or low depending on the sense
programmed), it will reset any Alarms and drop out any Contact closures. Note: The alarms need to be set up correctly
(see Section 4.4).
4.3 Decimal Point
The decimal point on the display may be fixed from 1 to 3 places or may be set to none (only whole number displayed). As
the display increases the unit will automatically drop decimals to show whole number values. Note that for values larger
than 99999 all decimal points light indicating the current reading is x10.
4.4 Alarm Limits
The ACT-3X has two independent alarm set points, referred to as LIMIT 1 and LIMIT 2 (Set 1 and Set 2 on the menu).
These limits are fully programmable by the user (unless the write protect option has been set). The limits may be set as high
or low with an option of low limit lockout, latching or non-latching at any value. The limits are accurate to better than
±0.1% of the set point value. Refer to Section 4.7.2 for the limit response time. The dead band (hysteresis) is also
programmable at any value from 0.0001 to 99.999% of the set point value. The actual output from these alarms is a set of
form C, dry contacts, accessible via barrier strip screw terminals on the rear panel. These contacts are capable of switching 1
A at 250 Vac. When the unit is making measurements, the limits can be viewed by pressing the UP  button for LIMIT 1
or the DOWN  button for LIMIT 2. The display will return to normal after a few seconds. The relays may also be set to
be Failsafe, which inverts the sense of the relay so that they are energized under normal condition. In the event of a power
failure the contacts will drop out as they would during an alarm condition. Refer to Section 5.0 to set limit set points.