The 5B32 is a single-channel signal conditioning module that amplifies, protects, filters and isolates its analog input. The module measures a process-current input signal of 4-20 mA or 0-20 mA by reading the voltage across an external precision 20 Ω resistor (supplied) and generating an output of 0 to +5 V. Extra current conversion resistors are available as accessories (See Model AC1362 in the Accessories section).
Note that the 5B32 module circuitry can withstand 240 V rms at the input screw-terminals, thereby shielding computer-side circuitry from field-side overvoltage conditions. In addition, all 5B32 Series modules are mix-and-match and hot swappable, so can be inserted or removed from any socket in the same backplane without powering down the system.
Inside the 5B32 Series Module
A chopper-stabilized input amplifier provides low drift and stable gain. At the amplifier input, a stable, laser-trimmed zero-scale input offset is subtracted from the input signal to set the zero-scale value for the 4-20 mA range. For user convenience, the zero can be optionally factory-set to meet custom needs. This allows suppression of a zero-scale input value many times larger than the total span for precise expanded-scale measurements.
Internal multi-pole lowpass filtering with a four-Hz cutoff (-3dB) enhances normal-mode (noise on signal) and common-mode (noise on signal return) rejection at 50/60 Hz, enabling accurate measurement of small signals in high electrical noise.
Signal isolation by transformer coupling uses a proprietary modulation technique for linear, stable and reliable performance. The differential input circuit on the field side is fully floating, eliminating the need for input grounding. A demodulator on the computer side of the signal transformer recovers the original signal, which is then filtered and buffered to provide a low-noise, low-impedance output signal. The output common must be kept within ±3 Vdc of power common.
A series output switch eliminates the need for external multiplexing in many applications. The switch is turned on by an active-low enable input. If the switch is to be on at all times, the enable-input should be grounded to power common as it is on the 5B01 and 5B08 backplanes.
2.275" x 2.375" x 0.595"
(57.8 mm x 59.1 mm x 15.1 mm)
-25°C to +85°C
-40°C to +85°C
-40°C to +85°C
0 to 93% @ +40°C noncondensing
±0.5% Span error @ 400 MHz, 5 Watt, 3 ft
1 Iz is the nominal input current that results in a 0 V output. 2 Includes the combined effects of repeatability, hysteresis, and nonlinearity and assumes RL > 50 kΩ. Does not include current-to-voltage input resistor (AC1362) error. 3 The output common must be kept within ±3 V of power common. 4 Loads heavier than 50 kΩ will degrade nonlinearity and gain temperature coefficient. 5 The current-to-voltage conversion resistor (AC1362) is supplied as a plug-in component for mounting external to the module. All backplanes and mounting cards provide pin sockets for mounting the AC1362 resistor.