4.   Hardware Installation

4.1.   Connecting Power to the APS Unit

The APS is available in both AC and DC powered versions. When connecting AC or DC power to the APS, proceed as follows:

  CAUTIONS:  

• This device should only be operated with the type of power source indicated on the instrument nameplate. If you are not sure of the type of power service available, please contact your local power company.
• Reliable earthing (grounding) of this unit must be maintained. Particular attention should be given to supply connections when connecting to power strips rather than directly to the branch circuit.

4.1.1.   AC Powered Units

The Voltage Selector Switch on the instrument back panel is used to set the unit for 115V or 230V AC power. Plug the supplied power cable into the receptacle on the APS back panel and then connect the power cable to a grounded AC outlet.

4.1.2.   DC Powered Units

The DC terminal block features two bus inputs as shown in Figure 4.1. This allows the user to connect only one DC power source, or connect two DC power sources where the second source functions as a backup. When connecting the APS-8M to your DC power source, first remove the protective cover from the terminal block, attach the wires from the -48V DC power source to the screw terminals, connect your ground line to the labeled ground screw, and then replace the protective cover.

Figure 4.1:   Terminal Block Assembly (DC Units Only)

4.2.   Configure SetUp Switches

The SetUp Switches are used to select default settings for the APS RS232 ports. The SetUp Switches are located on the APS-8M back panel, as shown in Figure 2.1.

When the APS-8M is shipped from the factory, the SetUp Switches are configured for 9600 baud, 8 Bits-No Parity, RTS/CTS handshaking, verbose command response, and command echo on (all switches ON). These settings are compatible with most applications. If the default settings are not compatible with your application, change the switch settings
as follows.

Notes:

• The SetUp Switches should be configured to match the parameters your control device will use when communicating with the APS-8M. This will ensure access to command functions, even if the unit is reset to default parameters.
• If the SetUp Switch configuration is changed, new parameters will not take effect until the unit is reinitialized as described in Section 4.3.
• Operating parameters (baud rate, parity, etc.) can be selected for each port using the /P command as described in Section 5.5. The /P command can select different parameters for each APS port.
• When the APS is initialized, parameters will return to settings specified by the SetUp Switches.

4.2.1.   Default Baud Rate  (Sw1, Sw2, Sw3)

SetUp Switches one through three select the default baud rate for RS232 Ports One through Seven. The default baud rate must match the rate your control device will use when communicating with the APS-8M.

Notes:

• If the control device will communicate via an external modem connected to one of the RS232 Ports, select a default baud rate that is compatible with the external modem.
• The /P command can also be used to select a different operating baud rate for each port.
• SetUp Switches one through three do not set the default baud rate for Port 8 (the Internal Modem Port). The default baud rate for Port 8 is 9600 bps. The operating baud rate for Port 8 can also be set via the /P command.

4.2.2.   Default Handshake  (Sw4, Sw5)

SetUp Switches four and five select the default handshake format for RS232 Ports One through Seven. The default handshake format must match the format your control device will use when communicating with the APS. SetUp Switches four and five can select RTS/CTS (hardware), XON/XOFF, Both or None.

Notes:

• If the control device will communicate with the APS-8M via an external modem connected to one of the RS232 ports, select a default handshaking format that is compatible with the external modem.
• The /P command can also be used to select a different handshake format for each port.
• Setup Switches Four and Five do not select the default handshake format for Port 8 (the Internal Modem Port). The default handshake format for Port 8 is RTS/CTS. The operating handshake format for Port 8 can also be set via the /P command.

4.2.3.   Default Response Message Format  (Sw6)

When commands are invoked, the APS-8M can respond with either verbose or terse (abbreviated) messages. Response messages are summarized in Section 11.2. After installation, the /P command can also set the response format to "none" (Quiet Mode). When Quiet Mode is selected, the unit will not send response messages. Note that the /P command can also be used to select a different Response Message format for each port.

4.2.4.   Default Command Echo  (Sw7)

Switch Seven enables or disables the Command Echo. When enabled, characters sent to the APS-8M will be echoed back to the control device. Note that the /P command can also be used to selectively enable or disable the Command Echo at each individual port.

Note:  SetUp Switch 8 is not currently used.

4.3.   Initialize Unit to Default Settings

If SetUp Switch settings are changed, new parameters will not take effect until the APS-8M is initialized.

CAUTION:  After initialization, the APS-8M will revert to the parameters specified by the SetUp Switches. Any command-selected parameters will be lost.

1. Simultaneously press the SET and CLEAR buttons, located on the face of the APS-8M.



2. Release the CLEAR button, wait for the Port LEDs to flash, and then release the SET button.

4.4.   Connecting Devices to the APS

APS RS232 Ports one through seven are standard DB9 connectors, configured as DTE Ports, and are similar to a standard serial port on a PC.

1. Access the APS-8M Command Mode.



2. Determine which RS232 port will be used for connection to the new device (e.g. Port 3).



3. Check Buffer:  Type /S [Enter] to display the Port Status Screen. Check the "Buffer Count" column, which lists the amount of data stored in the buffer for each port.



1. If the Port Status Screen shows data stored in the buffer for the desired port, type /E xx [Enter] to clear the buffer (where xx is the desired port number).



2. Note that cleared data cannot be recovered.



4. Use an appropriate DB9 cable to connect the RS232 serial port on the device to the selected DB9 port on the APS.



1. External Modems and other DCE Devices:  Use a standard serial modem cable.



2. PCs and other DTE Devices:  Use a standard null modem cable.



5. Select communication parameters for the port as described in Section 5.