US Digital

SEI-USB SEI to USB Adapter

Overview

  • USB 1.1 device communicates at 12 Mbit/sec
  • Compatible with USB 2.0 hubs and host adapters
  • USB drivers are included for Windows 2000 / XP / Vista
  • Supports up to 15 total devices on the SEI bus
  • Supports SEI bus lengths up to 1000 feet, depending on the number of devices attached.
  • USB port on the PC provides power for the SEI-USB and SEI bus devices (120mA max using USB port power).
  • Short-circuit power protection between the USB port and the SEI bus.
  • Includes two LED indicators: green for USB power-sense and red to indicate additional external power is required.

Product Specifications

ParameterMin.Typ.Max.UnitsPort / PinNotes
External Supply Voltage (optional) 8.5 12 16.0 V J3 The external supply is used when the USB port power (J1) is not adequate to provide sufficient power when a large number of SEI devices are connected to the SEI-USB.
External Supply Current (optional) - - 1500 mA J3 -
SEI-USB PWR Pin Voltage 8.0 9.5 10.5 V P1 / 4 Generated by the SEI-USB using the USB port power (J1). Assumes that the USB PWR pin is not in a current limit mode as indicated by the red power-fault LED.
SEI-USB PWR Pin Current - - 120 mA P1 / 4 Adequate to directly power five A2 encoders at a distance of 250 feet.
USB Port PWR Current, No Devices <0.5 17 20 mA J1 / 1 SEI-USB device load only, no devices attached.
USB Port PWR Current, 5 A2 Devices - 275 480 mA - With 5 A2 devices attached.
Differential SEI Output Voltage 2.0 3.2 5.0 V P1 / 5, 6 -
Differential SEI Input Voltage 0.2 - 5.0 V P1 / 2, 3 and P1 / 5, 6 -
Common-mode SEI Output Voltage 2.0 2.5 3.0 V P1 / 5, 6 -
Common-mode SEI Input Voltage -4.5 - 3.0 V P1 / 2, 3 and P1 / 5, 6 -
SEI Input Current (In=0-5V) -15 - 15 mA P1 / 2, 3 and P1 / 5, 6 -
USB Enhanced ESD protection - - 15 kV - Human body model.
ParameterMin.Typ.Max.UnitsPort / PinNotes
Data Rate 1.2 - 115.2 kBaud P1 / 5, 6 Virtual COM port speed.

Data Latency: The USB data latency timer is preset to a default value of 16ms by the driver manufacturer. This means that data could be sitting in the FIFO buffer up to 16ms before it is forced to transmit. If Windows is allowed to search the internet for the device drivers when the "Found New Hardware" wizard is displayed, then the latency timer will be set to 16ms. The latency timer can be set to a minimum of 1ms using USBSpeedBoost software found on the product installation CD or here. If the drivers are installed from the installation CD, then the latency timer will automatically be set to a minimum of 1ms.

ParameterMin.Max.Units
Storage Temperature -40 100 C
Operating Temperature 0 70 C
Humidity (non-condensing) 0 95 %

P1 SEI Port

PinNameDescription
1 GND Ground, common for power, data and busy pairs
2 Busy+ Differential input line, active high, has 330 Ω pull down
3 Busy- Differential input line, active low, has 330 Ω  pull up
4 PWR Power supply output to encoder bus (USB or external)
5 DataL Bidirectional differential data line, has 330 Ω  pull up
6 DataH Bidirectional differential data line, has 330 Ω  pull down

J1 USB Port

PinNameDescription
1 PWR USB power input (4.75 - 5.25V @ 500mA)
2 D- USB data - line
3 D+ USB data + line
4 GND USB ground

Product Description

Restriction of Hazardous Substances

The SEI-USB is an interface module that connects US Digital's SEI compatible devices to a standard USB 1.1 / 2.0 port.

The SEI (Serial Encoder Interface) bus is a simple, quick and convenient network that connects up to 15 addressable SEI devices using a single 6-wire telephone-type cable up to 1000 feet long. The SEI bus uses two RS-485-like differential pairs, one for busy flow control, and the other for bi-directional serial data (see the SEI data sheet).

The SEI-USB will supply power from the USB port to a modest number of SEI devices on the bus (for example, five A2 encoders at a distance of 250 feet). The SEI-USB limits the power to the maximum design spec of the USB port. A red LED, next to the SEI connector, will be lit when additional power is required and the PS-12 power supply should then be used.  A green LED, next to the USB connector, is lit when the USB connection is established with the host.

Product Notes
  • US Digital warrants its products against defects in materials and workmanship for two years. See complete warranty for details.
Related Documentation

Purchasing

Configure and Purchase

Product Part Number
Quantity Price
1 $49.00
10 $45.94
50 $40.83
100 $37.77
Over 100 Call for quote
Quantity
Unit Price

$49.00

Subtotal

$49.00

For your convenience, use the above part number to order via phone 800.736.0194

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