The PureAire Monitoring Systems ST-71 Graphic Display / Alarm Controller is designed to provide simultaneous display and alarm functions for up to 72 input variables. A graphic LCD displays monitored data as trends, bar graphs, and engineering units. Three adjustable alarm levels are provided per channel. Relay outputs allow control of beacons horns and other alarm events. A horn relay may be set for steady or pulsing operation.
Analog inputs may be accepted and conditioned via sensor-specific analog input cards. Alternatively, the standard Modbus Master port allows input data to be retrieved from Modbus slave devices including the many Modbus compatible PureAire Monitoring sensor transmitter products.
The ST-71 is easy to configure and user friendly. Measurement ranges in engineering units, adjustable alarm set-points, dual serial interfaces, and many other features combine to allow the ST-71 to satisfy the needs of many demanding applications. It is widely used for centralizing the display and alarm processing functions in critical multipoint monitoring applications. These include monitoring of ambient gas detection, rotating machinery, tank levels, flow, temperature, and others.
An RS-485 Modbus slave port allows up to 128 ST-71’s to be multi-dropped onto a single data highway for interrogation by another Modbus master. ST-71’s may also be cascaded by connecting one unit’s master port to another’s slave port.
ST-71 options such as discrete alarm relays per channel, 4- 20mA I/O, direct sensor input conditioning, and others are added by connecting appropriate 8 channel boards (2 required for more than 8 channels) to the economical I2C expansion bus. Familiar “telephone style” cables and connectors interface to this bus. This method allows a versatile system configuration of options satisfying the most unusual user applications.
Nonvolatile memory retains all configuration data indefinitely.
# ST-71PM panel/rack mount housing
# ST-71N4 NEMA 4X wall mount
# ST-71XP NEMA 7 wall mount explosion-proof housing
PureAire Monitoring sensor transmitter products.
The ST-71 is easy to configure and user friendly. Measurement ranges in engineering units, adjustable alarm
- # ST-71PM panel/rack mount housing
- # ST-71N4 NEMA 4X wall mount
- # ST-71XP NEMA 7 wall mount explosion-proof housing
- Accepts up to 16 inputs from many sensor types and signal ranges. Inputs may be analog, or Modbus® Master capability allows input data to be retrieved via RS-485 data highway reducing wiring costs at installation
- 8 channel display mode and option boards allow economical configuration of systems requiring only 8 channels or less
- Dual Modbus RS-485 serial ports for simultaneous master/slave operation. Optional phone modem
- 3 independent alarm levels per channel. Relay Acknowledge feature allows silencing of external audible devices during existing alarm conditions
- Graphic LCD readout displays monitored data as trends, bar graphs, and engineering units. Alarm LED’s flash when new and acknowledged
- Standard A SPDT common alarm relays for HORN, HIGH, WARN & FAULT. Optional discrete channel alarm relays also available
- Options such as alarm event printer interface, direct sensor inputs, 4-20mA outputs, discrete alarm relays, and others are supported via an I2C expansion bus
- Cal Mode offers pushbutton zero / span calibration for direct sensor interface applications. Authorizat- Mode allows locking of critical configuration variables
- Magnetic keypad available for nonintrusive operation in potentially hazardous locations
- NEMA 4X, Explosion-Proof, surface mount, panel, and rack mount packaging options available