Core Technical Specifications
| Parameter | Value |
|---|---|
| Model Number | 3721 |
| Product Name | Dual 1×20 Multiplexer Card (for 3700A Mainframe) |
| Channel Configuration | 2 independent banks × 20 two‑pole channels (40 two‑pole total; 20 four‑pole optional) |
| Dedicated Current Channels | 2 channels (3A max carry, 1A max switch) |
| 4‑Wire Ohms Support | 40 channels (common‑side 4‑wire input) |
| Signal Connectors | 2 × 50‑pin male D‑sub (signal I/O) |
| Relay Type | Electromechanical (reed/armature, long life) |
| Relay Counting | Onboard non‑volatile memory (auto‑counts closures) |
| Max Voltage (Signal) | 300 VDC / 250 VAC (rms) |
| Max Current (Signal) | 1 A (switching); 3 A (carry only) |
| Max Power | 60 W (resistive) |
| On/Off Resistance | <0.5 Ω (closed); >10¹² Ω (open) |
| Isolation Voltage | 1500 VDC (channel‑to‑channel, channel‑to‑ground) |
| Bandwidth | DC to 10 MHz (typical) |
| Operating Temp | 0 °C to +50 °C |
| Storage Temp | -40 °C to +70 °C |
| Humidity | 0–90% RH (non‑condensing) |
| Dimensions (W×H×D) | Fits 3700A card slot (standard width) |
| Weight | ~0.5 kg |
| Certifications | CE, UL, cUL |
Key Features & Capabilities
- High Channel Density: 40 two‑pole or 20 four‑pole channels in a single card, ideal for multi‑sensor/ multi‑signal test systems.
- Flexible Routing: Two independent banks for parallel testing; dedicated current channels for high‑current signal paths.
- 4‑Wire Resistance Measurement: Built‑in support for 4‑wire ohms (Kelvin) to eliminate lead resistance errors.
- Reliability & Diagnostics: Relay closure counting for predictive maintenance; non‑volatile memory retains counts after power loss.
- Seamless Integration: Plugs directly into 3700A mainframe; controlled via GPIB, LAN, USB, or front panel; compatible with Test Script Builder (TSB) and standard SCPI commands.
Interfaces & Compatibility
- Mainframe Interface: 3700A backplane (analog + control bus)
- Signal I/O: 2 × 50‑pin male D‑sub (screw terminal or ribbon cable compatible)
- Control Interfaces: GPIB (IEEE‑488.2), LAN (LXI), USB, front panel
- Software Compatibility: Test Script Builder (TSB), LabVIEW, MATLAB, Python, and any SCPI‑compliant test software
- Mainframe Compatibility: Keithley/Tektronix 3706A, 3706A‑NET, 3706A‑SYSTEM, 3706A‑MULTISLOT
