Advanced Measurement Technology 273A, Руководство пользователя

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56
Model 273A Potentiostat/Galvanostat User’s Manual
Notes: The E MONITOR and OUTPUT lines are driven by the same
signals as are present at the front-panel E MONITOR and OUTPUT
connectors.
When operating under front-panel control, the Pen-Drop relay contacts
close when [START] or [CONTINUE] is pressed. Pressing [STOP] or
[HOLD] causes the contacts to open. Under computer control (RS-232C
or GPIB port), the pen contact closure is controlled by the PEN
command.
A.3. Auxiliary Interface (mating connector DB9S)
This connector provides several functions only available when the Model 273A is being
controlled from an external computer via the RS-232C or GPIB (IEEE-488) port. Included are the
signals required to drive a Model 303A Static Mercury Drop Electrode. If this electrode is used,
connections between the Auxiliary Interface and the Model 303A are made via the Model 307
Interface.
This accessory allows the Model 273A to be used in conjunction with the Model 303A Static
Mercury Drop Electrode by providing three cables (all hard-wired to the Model 307) to make the
necessary connections. One cable connects to the Model 273A AUXILIARY INTERFACE
connector, the second connects to the Model 273A CELL INTERFACE connector, and the third
connects to the Model 303A INPUT connector. A 0.1 A fast-blow fuse is provided in the Counter
Electrode line. The Model 307 requires externally su24 V at 1 A.
PI SIGNAL FUNCTION
N
1 ground
2 EXT TRIG. This input allows an operation in progress to be halted via the WFT command from an external
computer. If the command WFT 0 is applied, operation will resume when a logic 0 is applied to the
EXT. TRIG line. If the command WFT 1 is applied, operation will resume when a logic 1 is applied
tot he EXT. TRIG line.
3 In applications where the Model 273A is being used with a Model 303A via a Model 307 Interface,
DISPENSE this signal causes the Model 303A to do a Dislodge/Dispense operation on command from an
external computer. The computer initiates the dispense operation by applying a DISP command
(see description in the Model 273A Remote-Programming Command Handbook).
4 TRIG OUT A TTL trigger output is provided on this line on application of the TRIG command. The Trig Out
baseline is either a logic 0 or a logic 1 (default is logic 0), according to the operand of the last
applied TRIG command. TRIG 0 establishes a logic 1 baseline. TRIG 1 establishes a logic 0
baseline. Once a logic 0 baseline is established, subsequent TRIG 1's will cause a 10 to 20 ms
wide logic 1 pulse to be generated. Similarly, once a logic 1 baseline is established, TRIG 0's will
cause a 10 to 20 ms wide logic 0 pulse to be generated.
5 BIT 0 IN The level on this line will be read and reported to the host computer if the command BIT 0 is
applied.
6 +5 V +5 V at up to 100 mA is available for external use.
7 BIT 0 OUT If Current Interrupt IR Compensation is NOT active, the level on this line will be set to a logic 0 if the
command BIT 0 0 is applied. It will be set to a logic 1 if the command BIT 0 1 is applied.
If Current Interrupt IR Comp. is active, this line will go high about 3 µs before the start of the current
interruption and will go low about 7 µs after the start of the current interruption. This pulse can be
used to trigger an osciloscope so that the IR Current Interrupt waveform can be easily monitored at
the rear-panel ELECTROMETER MONITOR connector.
8 When operating a Model 273A with a Model 303A SMDE via a Model 307 Interface, this signal
PURGE controls the Model 303A's purge function in response to commands from the external computer.
The computer initiates a purge by applying a PURGE command (see discussion of this command
in the Model 273A Remote Programming Command Handbook).