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.
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.
Figure 1. 5B32 Functional Block Diagram
Figure 2. 5B32 Input Field Connections
|
4 mA to 20 mA |
Output Ranges 0 to +5 V |
| Model | Input Range | Output Range | |
|---|---|---|---|
| Order Now | 5B32-01 | 4 mA to 20 mA | 0 V to +5 V |
| Order Now | 5B32-02 | 0 mA to 20 mA | 0 V to +5 V |
| 5B32-Custom | * | * |
| Description | Model 5B32 |
|---|---|
| Input Ranges | |
| Standard Ranges | 0 mA to 20 mA or 4 mA to 20 mA |
| Custom Ranges | 0 mA to 20 mA (refer to ordering section) |
| Output Ranges (RL > 50 kΩ)4 | -5 V to +5 V or 0 V to +5 V |
| Accuracy2 | |
| Initial @ +25°C | ±0.05% Span ±0.05% Iz1 |
| Nonlinearity | ±0.02% Span |
| Input Offset vs. Temperature | ±0.0025 of Iz/°C |
| Output Offset vs. Temperature | ±20 µV/°C |
| Gain vs. Temperature | ±0.0025% of Reading/°C |
| Input Resistor5 | |
| Value | 20.0 Ω |
| Accuracy | ±0.1% |
| Stability vs. Temperature | ±0.001%/°C |
| Noise | |
| Input, 0.1 Hz to 10 Hz Bandwidth | 10 nA rms |
| Output, 100 kHz Bandwidth | 200 µV rms |
| Bandwidth, -3 dB | 4 Hz |
| Output Rise Time, 10% to 90% Span | 200 ms |
| Common-Mode Voltage (CMV)3 | |
| Input-to-Output, Continuous | 1500 V rms maximum |
| Output-to-Power, Continuous | ±3 V maximum |
| Transient | ANSI/IEEE C37.90.1-1989 |
| Common Mode Rejection (CMR) | |
| 1 kΩ Source Imbalance, 50/60 Hz | 160 dB |
| Normal Mode Rejection 50/60 Hz | 60 dB |
| Input Protection | |
| Continuous | 240 V rms maximum |
| Transient | ANSI/IEEE C37.90.1-1989 |
| Output Resistance4 | 50 Ω |
| Voltage Output Protection | Continuous Short to Ground |
| Output Selection Time | 6 µs @ Cload = 0 to 2,000 pF |
| Output Enable Control | |
| Max Logic "0" | +1 V |
| Min Logic "1" | +2.5 V |
| Max Logic "1" | +36 V |
| Input Current "0" | 0.4 mA |
| Power Supply Voltage | +5 V ±5% |
| Power Supply Current | 30 mA |
| Power Supply Sensitivity, RTI | ±2 µV/Vs% |
| Mechanical Dimensions | 2.275" x 2.375" x 0.595" (57.8 mm x 59.1 mm x 15.1 mm) |
| Environmental | |
| Temperature Range | |
| Rated Performance | -25°C to +85°C |
| Operating | -40°C to +85°C |
| Storage | -40°C to +85°C |
| Relative Humidity | 0 to 93% @ +40°C noncondensing |
| RFI Susceptibility | ±0.5% Span error @ 400 MHz, 5 Watt, 3 ft |
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