| Technical specifications |
| DIGITAL INPUT/OUTPUT |
| Digital type | Input: 74ACT373 Output: 74FCT244 |
| Number of I/O | 24 ports (Port A Bit 0 through Port C Bit7) |
| Configuration | 2 banks of 8 and 2 banks of 4, or 3 banks of 8 |
| Pull-up/down configuration | all pins pulled up to 5V via 47 kO resistors (default). Selection available for pull down to ground. Hardware selectable via 0 O resistor |
| Input high voltage | 2.0 V min, 5.5 V absolute max |
| Input low voltage | 0.8 V max, -0.5 V absolute voltage |
| Output high voltage | 3.0 V min |
| Output low voltage | 0.55 V max |
| Source current | Self-powered hub or externally powered root port hub:15 mA per output, max. Bus-powered or battery-powered root port hubs are not supported. |
| Power up / reset state | Input mode |
| COUNTER |
| Pin name | CTR; Schmitt trigger input. |
| Counter type | Event counter |
| Number of channels | 1 |
| Input type | TTL, rising edge triggered |
| Input source | CTR Screw terminal |
| Resolution | 32 |
| Schmidt trigger hysteresis | 20 mV to 100 mV |
| Input leakage current | +-1 µA |
| Maximum input frequency | 1 MHz |
| High pulse width | 500 ns min |
| Low pulse width | 500 ns min |
| Input low voltage | 0 V min, 1.0 V max |
| Input high voltage | 4.0 V min, 15.0 V max |
| DATA TRANSFER RATES |
| Digital I/O transfer rates (software paced) | Digital input: () 62 port reads or single bit reads per second (typ) Digital output: 125 port writes or single bit writes per second (typ) |
| Counter/timer read/write rates (software paced) | Counter read: 62 port reads per second (typ) Digital output: 125 port writes per second (typ) |
| POWER |
| Supply current | 100 mA typ, 135 mA max. (Total current; no load) |
| USB +5V power available | Connected to self-powered hub (350 mA) – (total output source current) Connected to bus-powered hub4.75 V min, 5.25 V max |
| Over-current protection | Resettable fuse Hold current: 350 mA, typ Trip current: 700 mA typ Trip/recovery time: 100 ms, max On resistance: 1.3 O max |
| GENERAL |
| USB Controller clock error | 25 °C: ±30 ppm max 0 °C to 70 °C: ±50 ppm max |
| Device type | USB 1.1 low-speed |
| Device compatibility | USB 1.1, USB 2.0 |
| ENVIRONMENTAL |
| Operating temperature range | 0 °C to 70 °C |
| Storage temperature range | –40 °C to 85 °C |
| Humidity | 0% to 90% non-condensing |
| MECHANICAL |
| Dimensions (L x W x H) | 119 × 84 × 14 mm (4.68 × 3.31 × 0.55 in.) |
| USB Cable length | 3 m (9.8 ft) |
| USB cable type | A-B cable, UL type AWM 2725 or equivalent. Min 24 AWG VBUS/GND, min 28 AWG D+/D– |