SEC 3500 HMI Operator Interface from Sensor Electronics

The SEC 3500 HMI is an operator interface dedicated to communicating to the SEC 3100 gas detector, SEC relay controllers, SEC 3100 AIM and SEC 3100 LIM units. The SEC 3500 has output capabilities to the plant control system. It uses an industry standard RS485 communication protocol to interrogate up to 254 Network Devices.


  • Intuitive graphical interface
  • 7.7″ 256 color 640 x 480 DSTN display
  • RS485 MODBUS RTU communication to SEC 3100
  • 10 Base-T/100 Base-TX ethernet port
  • Configuration and firmware are stored in 8MB of non-volatile FLASH memory
  • CompactFlash socket to increase memory capacity
  • Dedicated MENU key and 6 soft keys
  • Power unit from 24VDC ±20% supply
  • Resistive analog touchscreen
  • Powerful 32-bit processor
  • Audible alarm
  • Remote web access and control facility
  • NEMA 4X/IP66 front panel
  • 16 programmable relays, expandable to 40
  • Interfaces with up to 254 network devices
  • “Stat Case” RS232 system status broadcast


Standard display screens are set up for intuitive interaction for the operator and network devices. The primary screens are Main Zone Summary, Alarm Summary, and Bus Summary. Individual device screens can be viewed and programmed from the SEC 3500 HMI. Password protected security ensures only authorized access to critical screens.


Operating Voltage 19 to 29 VDC
Power Consumption 40 Watt Maximum, not including relay
Contact current or 24VDC supplied to external relays
Temperature Rating Operating: 0 to 50°C
Storage: -25 to 60°C
Humidity 0-80% rH
Altitude Up to 2,000 meters
Interface RS485: Interactive MODBUS, expandable to 2
RS232: “Stat Cast” system parameter broadcast
Ethernet: Remote screen access 10 Base-T/100 Base-TX
RJ45 jack wired as network interface card
16 programmable relays, expandable to 40
Relay Contacts 1 NO, 1 NC per relay
Contact rating: 8A @ 30 VDC, 8A @ 250 VAC
Audible Alarm Alarm and fault
Display Type: DSTN
Colors: 256 VGA
Pixels: 640 x 480
Brightness: 120 cd/m2
Backlight: 40,000 hours typical
Battery Lithium coin cell
Memory 8 Mbyte non-volatile
Memory Card Compact Flash Type II slot for Type I and Type II Compact Flash cards
Enclosure Powder coated steel
Dimensions 16″ W x 16″ L x 10″ D
Weight 45 pounds
Relay Contacts Cat 1, Pollution Degree 2
Approvals CSA: C22.2 No 0, No 0.4-4, No 14-05, No 142, UL 508

Ordering Information

For pricing, please call AFC International at 1-800-952-3293, 219-987-6825 or fax 219-987-6826 or email


SEC3500 HMI Literature

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