Figure 2-1 (click on the specific Fig.2-1 location to hot-link to the corresponding detailed jumper Figure)
Lab-PC+ User Manual, © National Instruments Corporation
Adapted for Web posting by Prof. M. Kostic
M. Kostic's NOTE:
We have to configure any plug-in DAQ board in order to choose among its different features, and for the board to properly communicate between two "worlds": (1) external "measurement world," or sensor's signals via the external cabling (analog I/O settings configuration); and (2) the DAQ board has to communicate internally with "PC world," via its bus-interface (PC bus interface configuration). Older boards require appropriate DIP switch and jumper settings and the corresponding software settings, while the newer, so called "plug-and-play" or PnP boards, are completely software configurable.
Chapter 2:
This chapter describes the Lab-PC+ jumper configuration, installation of the Lab-PC+ board in your computer, signal connections (see Demo-box pin-terminal connections) to the Lab-PC+, and cable wiring.
Board Configuration
The Lab-PC+ contains six jumpers and one DIP switch to configure the PC bus interface and analog I/O settings. The DIP switch is used to set the base I/O address. Two jumpers are used as interrupt channel and DMA selectors. The remaining four jumpers are used to change the analog input and analog output circuitry. The jumpers are shown in the parts locator diagram in Figure 2-1 (click on the specific Fig.2-1 location to link to the corresponding detailed jumper Figure). Jumpers W3 and W4 configure the analog input circuitry. Jumpers Wl and W2 configure the analog output circuitry. Jumpers W6 and W5 select the DMA channel and the interrupt level, respectively.
PC Bus Interface
The Lab-PC+ is configured at the factory to a base I/O address of hex 260, to use DMA Channel 3, and to use interrupt level 5. These settings (shown in Table 2-1) are suitable for most systems. If your system, however, has other hardware at this base I/O address, DMA channel, or interrupt level, you will need to change these settings on the other hardware or on the Lab-PC+ as described in the following pages. Record your settings in the Lab-PC+ Hardware and Software Configuration Form in Appendix E.
Figure 2-1 (click on the specific Fig.2-1 location to hot-link to the corresponding detailed jumper Figure)
Table 2-1. PC Bus Interface Factory Settings:
The base I/O address for the Lab-PC+ is determined by the switches at position U1 (see Figure 2-1). The switches are set at the factory for the base I/O address hex 260. This factory setting is used as the default base I/O address value by National Instruments software packages for use with the Lab-PC+. The Lab-PC+ uses the base I/O address space hex 260 through 27F with the factory setting.
Note: Verify that this space is not already used by other equipment installed in your computer. If any equipment in your computer uses this base I/O address space, you must change the base I/O address of the Lab-PC+ or of the other device. If you change the Lab-PC+ base I/O address, you must make a corresponding change to any software packages you use with the Lab-PC+. Table 2-2 lists the default settings of other National Instruments products for the PC. For more information about the I/O address of your PC, refer to the technical reference manual for your computer.
Each switch in Ul corresponds to one of the address lines A9 through A5. Press the side marked OFF to select a binary value of 1 for the corresponding address bit. Press the other side of the switch to select a binary value of 0 for the corresponding address bit. Figure 2-2 shows two possible switch settings. The shaded portion indicates the side of the switch that is pressed down.
Figure 2-2. Example Base I/O Address Switch Settings:
Note: The shaded portion indicates the side of the switch that is pressed down.
The five least significant bits of the address (A4 through AO) are decoded by the Lab-PC+ to select the appropriate Lab-PC+ register. To change the base I/O address, remove the plastic cover on U1; press each switch to the desired position; check each switch to make sure the switch is pressed down all the way; and replace the plastic cover. Notice the new Lab-PC+ base I/O address for use when configuring the Lab-PC+ software in Appendix E, Customer Communication. Table 2-2 lists the default settings of National Instruments products for the PC.
Table 2-2. Default Settings of National Instruments Products for the PC:
Table 2-3 lists the possible switch settings, the corresponding base I/O address, and the base I/O address space used for that setting.
Table 2-3. Switch Settings with Corresponding Base I/O Address and Base I/O Address Space:
The Lab-PC+ uses the DMA channel selected by jumpers on W6 (see Figure 2-1). The Lab-PC+ is set at the factory to use DMA Channel 3. This is the default DMA channel used by the Lab- PC+ software handler. Verify that other equipment already installed in your computer does not use this DMA channel. If any device uses DMA Channel 3, change the DMA channel used by either the Lab-PC+ or the other device. The Lab-PC+ hardware can use DMA Channels 1, 2, and 3. Notice that these are the three 8-bit channels on the PC I/O channel. The Lab-PC+ does not use and cannot be configured to use the 16-bit DMA channels on the PC AT I/O channel.
Each DMA channel consists of two signal lines as shown in Table 2-4.
Table 2-4. DMA Channels for the Lab-PC+ :
Two jumpers must be installed to select a DMA channel. The DMA Acknowledge and DMA Request lines selected must have the same number suffix for proper operation. Figure 2-3 displays the jumper positions for selecting DMA Channel 3.
Figure 2-3. DMA Jumper Settings for DMA Channel 3 (Factory Setting)
If you do not want to use DMA for Lab-PC+ transfers, then place the configuration jumpers on W6 in the position shown in Figure 2-4.
Figure 2-4. DMA Jumper Settings for Disabling DMA Transfers
The Lab-PC+ board can connect to any one of the six interrupt lines of the PC I/O channel. The interrupt line is selected by a jumper on one of the double rows of pins located above the I/O slot edge connector on the Lab-PC+ (refer to Figure 2-1). To use the interrupt capability of the Lab-PC+, you must select an interrupt line and place the jumper in the appropriate position to enable that particular interrupt line.
The Lab-PC+ can share interrupt lines with other devices by using a tristate driver to drive its selected interrupt line. The Lab-PC+ hardware supports interrupt lines IRQ3, IRQ4, IRQ5, IRQ6, IRQ7, and IRQ9.
Note: Do not use interrupt line 6. Interrupt line 6 is used by the diskette drive controller on most IBM PC and compatible computers.
Once you have selected an interrupt level, place the interrupt jumper on the appropriate pins to enable the interrupt line.
The interrupt jumper set is W5. The default interrupt line is IRQ5, which you select by placing the jumper on the pins in row 5. Figure 2-5 shows the default interrupt jumper setting IRQ5. To change to another line, remove the jumper from IRQS and place it on the new pins.
Figure 2-5. Interrupt Jumper Setting IRQ5 (Factory Setting)
If you do not want to use interrupts, place the jumper on W5 in the position shown in Figure 2-6. This setting disables the Lab-PC+ from asserting an interrupt line on the PC I/O channel.
Figure 2-6. Interrupt Jumper Setting for Disabling Interrupts
The Lab-PC+ is shipped from the factory with the following configuration:
Table 2-5 lists all the available analog I/O jumper configurations for the Lab-PC+ with the factory settings noted.
Table 2-5. Analog I/O Jumper Settings
Two ranges are available for the analog outputs-bipolar: ± 5 V and unipolar: 0 to 10 V. Jumper W1 controls output Channel 0, and W2 controls output Channel l.
Bipolar Output Selection
You can select the bipolar (± 5 V) output configuration for either analog output channel by setting the following jumpers:
| Analog Output Channel 0 | W1 | A-B |
| Analog Output Channel 1 | W2 | A-B |
This configuration is shown in Figure 2-7. 
Figure 2-7. Bipolar Output Jumper Configuration (Factory Setting)
Unipolar Output Selection
You can select the unipolar (0 V to 10 V) output configuration for either analog output channel by setting the following jumpers:
| Analog Output Channel 0 | W1 | B-C |
| Analog Output Channel 1 | W2 | B-C |
This configuration is shown in Figure 2-8.
Figure 2-8. Unipolar Output Jumper Configuration
You can select different analog input configurations by using the jumper and register bit (software) settings as shown in Table 2-5. The following sections describe each of the analog input categories in detail.
Input Mode
The Lab-PC+ features three different input modes – referenced single-ended (RSE) input, non- referenced single-ended (NRSE) input, and differential (DIFF) input. The single-ended input configurations use eight channels. The DIFF input configuration uses four channels. These configurations are described in Table 2-6.
Table 2-6. Input Configurations Available for the Lab-PC+
While reading the following paragraphs, you may find it helpful to refer to the Analog Input Signal Connections section, later in this chapter, which contains diagrams showing the signal paths for the three configurations.
DIFF Input (Four Channels)
DIFF input means that each input signal has its own reference, and the difference between each signal and its reference is measured. The signal and its reference are each assigned an input channel. With this input configuration, the Lab-PC+ can monitor four differential analog input signals. To select the DIFF mode, you must set the SE/D bit as described in the Command Register 4 bit description in Chapter 4, Register Map and Descriptions. You must also set the following jumper.
W4: B-C Jumper is in stand-by position, and negative input of instrumentation amplifier is tied to multiplexer output.
This configuration is shown in Figure 2-9.
Figure 2-9. DIFF Input Configuration
Considerations in using the DIFF configuration are discussed in the Signal Connections section later in this chapter. Figure 2-10 shows a schematic diagram of this configuration. Note that the signal return path is through the negative terminal of the amplifier and through Channels 1, 3, 5, or 7, depending on which channel pair was selected.
RSE Input (Eight Channels, Factory Setting)
RSE input means that all input signals are referenced to a common ground point that is also tied to the analog input ground of the Lab-PC+. The negative input of the differential amplifier is tied to analog ground. This configuration is useful when measuring floating signal sources. See Types of Signal Sources later in this chapter. With this input configuration, the Lab-PC+ can monitor eight different analog input channels. To select the RSE input configuration, clear the SE/D bit as described in the Command Register 4 bit description in Chapter 4, Register Map and Descriptions. You must also set the following jumper.
W4: A-B Jumper connects the negative input of the instrumentation amplifier to analog ground.
Figure 2-10 shows a schematic diagram of the RSE configuration.
Figure 2-10. RSE Input Configuration
Considerations in using the RSE configuration are discussed in the Signal Connections section later in this chapter. Note that in this mode, the return path of the signal is analog ground, available at the connector through pin AISENSE/AIGND.
NRSE Input (Eight Channels)
NRSE input means that all input signals are referenced to the same common mode voltage, which is allowed to float with respect to the analog ground of the Lab-PC+ board. This common mode voltage is subsequently subtracted out by the input instrumentation amplifier. This configuration is useful when measuring ground-referenced signal sources. To select the NRSE input configuration, clear the SE/D bit as described in the Command Register 4 bit description in Chapter 4, Register Map and Descriptions. You must also set the following jumper.
W4: B-C Jumper is in standby position, and negative input of instrumentation amplifier is tied to multiplexed output.
Figure 2-11 shows a schematic diagram of this configuration.
Figure 2-11. NRSE Input Configuration
Considerations in using the NRSE configuration are discussed in the Signal Connections section later in this chapter. Note that in this mode, the return path of the signal is through the negative terminal of the amplifier, available at the connector through the pin AISENSE/AIGND.
Analog Input Polarity Configuration
Go to TOPTwo ranges are available for the analog inputs–bipolar +5 V and unipolar 0 to 10 V. Jumper W3 controls the input range for all eight analog input channels.
Bipolar Input Selection
You can select the bipolar (±5 V) input configuration by setting the following jumper:
Analog Input: W3; A-B
This configuration is shown in Figure 2-12.
Figure 2-12. Bipolar Input Jumper Configuration (Factory Setting)
Unipolar Input Selection
You can select the unipolar (0 to 10 V) input configuration by setting the following jumper:
Analog Input W3 B-C
This configuration is shown in Figure 2-13.
Figure 2-13. Unipolar Input Jumper Configuration
Note: If you are using a software package such as NI-DAQ or Lab-Windows, you may need to reconfigure your software to reflect any changes in jumper or switch settings.
The Lab-PC+ can be installed in any available 8-bit or 16-bit expansion slot in your computer. After you have changed (if necessary), verified, and recorded the switches and jumper settings, you are ready to install the Lab-PC+. The following are general installation instructions, but consult your PC user manual or technical reference manual for specific instructions and warnings.
The Lab-PC+ board is installed and ready for operation.
Lab-PC+ User Manual, © National Instruments Corporation