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Performance Tests
7
7-17
Send the command: DIO_LEVELS? <CR>
Verify the returned value is 253.
5. Repeat step 4 for each input and verify the correct returned value (See Table 7-7).
Table 7-7. Digital Input Values
TERMINAL GROUNDED STATE OF DIGITAL INPUTS DECIMAL VALUE
none inputs 0-7, all HIGH 255
0 inputs 1-7 HIGH, input 0 LOW 254
1 inputs 0,2-7 HIGH, input 1 LOW 253
2 inputs 0-1 and 3-7 HIGH, input 2 LOW 251
3 inputs 0-2 and 4-7 HIGH, input 3 LOW 247
4 inputs 0-3 and 5-7 HIGH, input 4 LOW 239
5 inputs 0-4 and 6-7 HIGH, input 5 LOW 223
6 inputs 0-5 and 7 HIGH, input 6 LOW 191
7 inputs 0-6 HIGH, input 7 LOW 127
Totalizer Test
This totalizer verification test requires toggling the Digital Output line 0 and using it as
the Total input. The test requires computer interfacing with a host (terminal or
computer). The host must send commands to the 2635A instrument to control the digital
line for this test. Refer to Chapter 4 for a description of configuring and operating Hydra
Series II.
1. Ensure that communication parameters ( i.e., transmission mode, baud rate, parity,
CTS, and echo mode) on Hydra Series II and the host are properly configured to
send and receive serial data. Refer to Chapter 4.
2. Switch OFF power to the instrument and disconnect all high voltage inputs.
3. Remove the Digital I/O ten-terminal connector from the rear of the instrument and
all external connections to it. Connect short wires (to be used as test leads) to the
DIGITAL I/O terminal 0 and the Total (SUM) terminal. Leave other ends of wires
unconnected at this time. Reinstall the connector.
4. Switch ON power to both Hydra Series II and the host.
5. Press the O button on the front panel of Hydra Series II.
Ensure that Hydra Series II displays a 0 value.
6. Jumper the DIGITAL I/O terminal 0 to the Total (SUM) input by connecting the
(SUM) terminal test lead to DIGITAL I/O 0’s test lead.
7. Using either a terminal or a computer running a terminal emulation program, set up
Hydra Series II to toggle (turn ON and OFF) Digital Output 0.
In sequence send the following commands to Hydra Series II and ensure that Hydra
Series II measures and displays the correct total value:
DO_LEVEL 0,0 <CR>
DO_LEVEL 0,1 <CR>
Ensure that Hydra Series II displays a totalizer count of 1.