Fluke 2625A, 2635A service manual Totalizer Sensitivity Test

Performance Testing and Calibration	4
Performance Tests

computer). The host must send commands to Hydra to control the digital line for this test.

1.Ensure that communication parameters (i.e., transmission mode, baud rate, parity, and echo mode) on Hydra and the host are properly configured to send and receive serial data. Refer to Section 4 of the Hydra Users Manual.

2.Switch OFF power to the instrument and disconnect all high voltage inputs.

3.Remove the ten-terminal Digital I/O connector from the rear of the instrument and

all external connections to it. Connect short wires (to be used as test leads) to the 0 terminal and the Totalizer ( ∑ ) terminal. Leave other ends of wires unconnected at this time. Reinstall the connector.

4.Switch ON power to both Hydra and the host.

5.Press the TOTAL button on the front panel of Hydra. Verify that Hydra displays a 0 value.

6.Jumper output 0 to the Totalizer ( ∑ ) input by connecting the ( ∑ ) terminal test lead to the output 0 test lead.

7.Using either a terminal or a computer running a terminal emulation program, set up Hydra to toggle (turn ON and OFF) Digital Output 0.

Send the following commands to Hydra in sequence, and verify that Hydra measures and displays the correct total value:

DO_LEVEL 0,0 <CR> DO_LEVEL 0,1 <CR>

Verify that Hydra displays a totalizer count of 1.

8.Send the following commands in sequence:

DO_LEVEL 0,0 <CR> DO_LEVEL 0,1 <CR>

A totalizer count of 2 should now be displayed.

9.Repeat step 8 for each incremental totalizing count.

10.Set the Hydra totalized count to a value near full range (65535) and test for overload. Send the following commands to Hydra:

TOTAL 65534 <CR> DO_LEVEL 0,0 <CR> DO_LEVEL 0,1 <CR>

A totalizer count of 65535 should be displayed.

11.Send:

DO_LEVEL 0,0 <CR> DO_LEVEL 0,1 <CR>

The Hydra display should now read "OL", indicating that the counter has been overrun.

4-17. Totalizer Sensitivity Test

1.Perform a successful Totalizer Test.

2.Remove the jumper connecting the ∑ terminal test lead to the output 0 test lead.

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