Alpha 912 RTD, Resistance and Voltage Input Module
€ - POA
Description
What is the Alpha 912 RTD, Resistance and Voltage Input Module?
The Alpha 912 provides 10 measurement channels at up to 19 bit resolution and 0.5uV integrity. It is fitted with general purpose dis connectable screw terminals and can be used to measure voltages, currents (using external shunts), standard Platinum RTD’s in 2,3, or 4 wire configurations and full bridge strain gauges.
The resistance mode can also be used for other resistive transducers. Strain gauge bridge offsets can be initialized.
The Alpha 912 module can be programmed to integrate signals to be measure over one or more complete mains cycle(50 – 60Hz) allowing the 912 to reject large levels of mains borne interference super imposed on micro-volt signals.
A choice of integration times and a digital filter that can be applied to any channel, together with the high stability circuitry achieve excelling noise performance and rejection.
The Alpha 912 supports an automatic range selection facility that enables maximum measurement sensitivity to be maintained for inputs that cross range thresholds.
Measurements are made continuously and can be returned in one of several formats most convenient for the supervisory software. Communications data rates up to 153KB are supported. All programming is stored in secure flash memory.
AUXILIARY INPUT/OUTPUTS
The 912 has three digital outputs and one digital input which can be used by a host as general purpose I/O or used internally by the firmware for a local function.
Example uses include, Synchronization to an external signal, or local indication of events or alarm conditions.
The standard firmware implements an alarm function that can be locally or remotely acknowledged. Specific operation can be easily programmed for custom applications.
Features
- Voltage, Current, Resistance and Strain
- 3 and 4 Wire RTD measurements in °C or °F
- 13 to 19 bit resolution. 200 to 10 measurements per second.
- Programmable Measurement Types
- Auxiliary I/O
- Scaling, alarm levels, filter functions.
- Second local programming and diagnostic interface.
- High speed communications.
Specifications
Specification Details
Number of channels / module: 10
Number of poles / channel: 4
Connector type input channel: Cage clamp 2 part screw terminal
Measurement modes:
Voltage: uV DC, mV DC
Resistance: Resistance 2 terminal, Resistance 4 terminal, PT100 3 terminal, PT100 4 terminal.
Strain full bridge: 350R, 120R
Overload Protection
Channel Overload Protection: Passive, 50V continuous, 150V short periods.
A-D Converters
5 Measurement resolutions are supported:
19 bits at 10 measurements/s
18 bits at 20 measurements/s
17 bits at 40 measurements/s
15 bits at 100 measurements/s
13 bits at 200 measurements/s
In addition a channel filter function can be applied to any channel. This can average the most recent four measurements.
Auxilary Channel Specification
Output switch ratings:
Outputs 1.2: 50mA @ 28VDC max, Non isolated, Suitable for driving small relays with isolated external supply.
Outputs 3 Relay Outputs: 1.0A at 48V AC/DC
Digital Input: Contract closure to 0V, External switch must be isolated.
Voltage Measurement
Input voltage ranges: +10V to -10V, +1.5V to -1.5V, +180mV to -180mV, +23mV to -23mV
Automatic range selection is supported.
DC Measurement accuracy: +/- 0.015% of reading +0.01% of range + 6uV
Temperature coefficients DC voltage: 25ppm rdg + 0.1uV/°C
Measurement sensitivity: <0.5uV on +23mV > -23mV range at 17bits
Note: Displayed sensitivity depends on reporting format. Additional error at 13bit 200/sec mode of 0.05% of range.
Power Requirement
Connector: 2-pole screw terminal
Voltage: 24V AC, 12-28V DC
Current: 200mA at 12V, 120mA at 24V
RTD Measurement
PT100
-50 TO 400°C +/- 0.2
-150 TO 600°C +/-0.4°C
General
RS485 Interface: See Manual, Baud rates to 153KB
RS232 Interface: RS232 Compatible Signals, RX TX 0 TO 5-volt signal levels, 9k6, 19k2 Baud, 8 bits, even parity, one stop bit, 3 pole screw connector.
Status LED’s: 7
Function Power / Fault
Communication RS485
Communication RS232
Outputs 1-3
Dig. Input 1
Size: 180 x 100 x 40mm
Weight: 400g
Mounting: DIN rain Stackable
Operating temperature range: – 20 to 70°C
Relative Humidity (non-condensing): <90% 0 to 40°C
Vibration: 3g 0hz to 400Hz in 3 planes
Programming storage: Secure flash memory Stated Accuracy’s are at 23°C
Interference Rejection
AC Common mode rejection ratio channel group: <0.1uV/V
AC Single channel common mode rejection ratio: <1uV/V
DC channel common mode rejection ratio: <5uV/V
AC series mode rejection ratio 50 or 60Hz +/- 0.05%: <1mV/V (Applies to 17,18,19 bit measurements).
Maximum voltages operating:
Max. voltage between any (+) and (-) inputs: 12V
Max. voltage between any two (-) input terminals: 11V
Max. voltage between any two terminals: 22V
Downloads
Alpha Server Brochure: [Brochure]
Alpha OPC Brochure: [OPC Brochure]
Alpha 912 Datasheet: [Datasheet]
