Frequency or Pulse Input Alarms

lifetime warranty
  • Lifetime Warranty on API Modules
  • LoopTracker® Input LED
  • Alarm Status LEDs
  • Hot-Swappable Plug-In Design
  • User Adjustable Setpoint(s)
  • Push to Test/Reset Alarms
  • Full I/O/Power Isolation
Click on PDF links below
for product information

Literature and Links


API product brochure
Options & accessories
Cross reference
See all frequency transmitters
Regulatory Compliance page

UL Approvals

API modules USA
API modules Canada

APD modules USA
APD modules Canada

Reference Info


Alarm terminology
Deadband
Relay protection & EMI suppression
RFI/EMI

How to Order

  1. Select a model
  2. See data sheet for ordering info and options
  3. Note that options affect pricing
  4. Request a quote via chat or call us
  5. 2-5 day typical lead time + shipping time
  6. 5-10 day lead time for quantities of 5 or more + shipping time
  7. To place your order
Model Input/Output Features Product

Frequency Input Alarm Trips


Factory Configured

API 1700 G  from $309

Open Datasheet
Download Datasheet
Specify input range
Factory configured
0-10 Hz to 0-20 kHz
100 mV to 150 VRMS amplitude change
Input must be self-powered or externally powered

API 1700 G Alarm Trip
One DPDT contact set, adjustable deadband
Standard: HI alarm
Optional: LO alarm

  • User adjustable setpoint(s)
  • 8 Amp contacts
  • Hot-swappable plug-in design
  • Input LoopTracker LED
  • Alarm status LEDs
  • Optional low alarm
  • Output test button
  • Uses API-011 11-pin socket
  • 115 VAC powered
  • A230 option for 230 VAC
  • P option for 85-265 VAC, 60-300 VDC power
  • D option for 9-30 VDC power


Api 1700G
API 1700 G

Frequency Input Alarm Trips


Factory Configured

APD 1700  from $289
APD 1720  from $309

Open Datasheet
Download Datasheet
Specify input range
Factory configured
0-25 Hz to 0-20 kHz
100 mV to 150 V RMS
Any waveform with minimum 100 mV amplitude change
Use with 2 wire, 3 wire NPN or PNP sensors

APD 1700 Single Alarm Trip
Dual SPDT contact sets
Standard: HI alarm, non-latching, normal acting
See data sheet for alarm options

APD 1720 Dual Alarm Trip
2 independent SPDT contact sets
Standard: HI/LO alarms, non-latching, normal acting
See data sheet for alarm options

  • Input sensitivity adjustment
  • 15 VDC sensor power available
  • User adjustable setpoint(s)
  • User adjustable deadband(s)
  • 8 Amp SPDT contacts
  • Input LoopTracker LED
  • Alarm status LEDs
  • Alarm options: LO, HI/HI, LO/LO, band alarm
  • Optional reverse acting
  • Optional latching alarms
  • Push to test/reset
  • Remote push to test/reset
  • Full I/O/power isolation
  • Removable plugs
  • DIN rail mount without tools
  • Universal power 85-265 VAC, 60-300 VDC
  • D option for 9-30 VDC, 10-32 VAC power

APD 1700 UL approved
APD 1700, APD 1720

Zero Speed (Stall) Monitor


Factory Configured

STM156  call for quote

Open Datasheet
Download Datasheet
Specify input type
Frequency input
Low level sine or sawtooth (200mVpp - 20Vpp)
24VDC pulse external source (0.2 - 50VDC)
NAMUR proximity sensor or contact (8V)
3-wire NPN proximity sensor 15V auxiliary
3-wire PNP proximity sensor 15V auxiliary
3-wire NPN proximity sensor 24V auxiliary
3-wire PNP proximity sensor 24V auxiliary
2-wire 24VDC/AC proximity sensor 24V auxiliary

Specify output type and options
Adjustable trip point and delays
One or two relays
Trip speed delay time range
Start up delay time range
External control options
  • Input includes external pulse and any type of speed sensor
  • Relay contact output
  • Front adjustments for trip speed and start-up delay
  • Status LED
  • Full I/O/power isolation
  • Universal power options: 8 VDC to 280 VAC
Typical applications include
  • Under speed alarm
  • Broken conveyor belt alarm
  • Machinery jam alarm
  • Stalled motor alarm
STM156
STM156