Measurement-computing USB-2627 Manual do Utilizador descarregar pdf (Página 16)

USB-2627 User's Guide Functional Details

40-pin header connectors J2, J4, and J5

The header connectors provide alternative connections to the SCSI connector.

 J2 provides connections for the analog inputs.

 J4 provides connections for the DIO, counter inputs, timer outputs, input scan clock, and power output.

 J5 provides connections for the analog outputs, timer outputs, I/O scan clocks, and power output.

Refer to Figure 4 and Figure 5 on page 12 for header connector pinouts.

USB connector

The USB connector provides +5 V power and communication. No external power supply is required.

LEDs

The USB-2627 has two LEDs – Power and Activity.

 The Power LED (top) turns on when the device is detected and installed on the computer.

 The Activity LED (bottom) blinks when data is transferred, and is off otherwise.

Standoffs

The board is shipped with standoffs that can be used for mounting onto a metal frame.

Signal descriptions

Analog input

The USB-2627 has a 16-bit A/D converter and provides 16 single-ended analog inputs. The input voltage range

is fixed at ±10 V. Analog input connections are available on the SCSI connector and on header connector J2:

 SCSI connector P1 provides connections for ACH0 to ACH15

 Header connector J2 provides connections for ACH0 to ACH15

Input pacer clock

You can pace input scanning operations using the input scan clock on the board or with an external signal

connected to XAPCR. The sampling rate is software-selectable for 0.0149 Hz to 1 MHz.

Channel-Gain queue

The USB-2627 channel-gain queue feature allows you to configure a list of channels to scan. The settings are

stored in a channel-gain queue list that is written to local memory on the device.

The channel-gain queue list can contain up to 16 elements. The channels can be listed in any order. An example

of a 4-element list is shown in the table below.

Sample channel-gain queue list

Element

Channel

Range

CH5

BIP10V

CH3

BIP10V

CH5

BIP10V

CH15

BIP10V

1 2 ... 11 12 13 14 15 16 17 18 19 20 21 ... 28 29

Sem comentários

Measurement-computing USB-2627 Manual do Utilizador Página 16