Advanced Measurement Technology 273A, Руководство пользователя

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Chapter 5—Operating Instructions 51
5.3.9. Multiplexed Output
This connector is used only in units equipped with the 273A/92 Electrochemical Impedance
Interface option. Either a current or voltage signal can be output from this connector as
determined by commands from an external computer via the GPIB or RS-232C port (refer to the
Model 273A Remote-Programming Command Handbook). Multiplexing is accomplished by
alternating the operand of the MIE command between "1" and "2" on successive iterations.
Note: This output is intended for use with Princeton Applied Research electrochemical
impedance systems.
5.3.10. AC Input
This connector, used only in units equipped with the 273A/92 Electrochemical Impedance
Interface option, accepts a sine wave input from an external oscillator, such as that supplied by a
Princeton Applied Research lock-in amplifier. The nominal frequency range is 50 µHz to 100
kHz, although this is dependent on cell impedance. Input voltage must be no greater than 5 volts
rms. This signal can be used to modulate the signal sent by the Model 273A to the cell, and can
be attenuated as desired. It is controlled by commands from an external computer via the GPIB
or RS-232C port (refer to the Model 273A Remote-Programming Command Handbook).
5.3.11. 273A/92 Electrochemical Impedance Interface Option
The 273A/92 Electrochemical Impedance Interface option (previously called the AC Interface
option) is intended primarily for use with Princeton Applied Research electrochemical
impedance systems, but can also be used for ac voltammetry applications. This option is
designed to allow superposition of an externally generated ac excitation signal on the dc signal
generated by the Model 273A.
The externally generated ac signal is input at the AC INPUT connector and is combined with the
signal generated by the Model 273A before it is applied to the cell. The /92 option board has
three output connectors (AC I OUTPUT, AC E OUTPUT, and MULTIPLEXED OUTPUT.
Software commands control both the mode of output (I, E, or multiplexed) as well as the type of
signal applied (full ac + dc signal or ac signal only). The Model 273A Remote-Programming
Command Handbook describes the computer commands used with the Model 273A/92 option.
5.3.12. RS-232C Interface
This connector and the associated switch assembly are used to establish serial RS-232C
communications between the Model 273A and a host computer. Instructions for remote operation
are given in the separately bound Model 273A Remote-Programming Command Handbook. The
adjacent switch assembly sets the user-controlled RS-232C parameters. See Appendices A and
D of the Command Handbook for additional information.
5.3.13. IEEE-488/GPIB Interface
This connector and the associated switch assembly are used to establish communications
between the Model 273A and a host computer via the GPIB port (IEEE-488). Instructions for
remote operation are given in the separately bound Model 273A Remote-Programming
Command Handbook. The adjacent switch is used to set the GPIB address and TEST ECHO
status, and allows for selection of the terminator. See Appendices B and C of the Model 273A
Command Handbook for detailed information.
5.4. Differential Electrometer
The electrometer (Fig. 9) acts as the interface between the Model 273A and the reference
electrode. A cable runs from the Electrometer Housing to the CELL INTERFACE connector at
the back of the Model 273A.
The various leads, switches, and jacks on the front of the housing are briefly discussed in the
following paragraphs.