Fluke 2620A Totalizer Test, Terminal Grounded, 7. Digital Input Values STATE OF DIGITAL INPUTS

Maintenance 6

Performance Tests

Verify that the returned value as shown on the Host screen = 255.

Note

The number returned is the decimal equivalent of the Digital Input binary word (inputs 0 through 7’s status). See Table 6-7 to determine if the number returned corresponds to the bits jumpered to ground in this test.

3.Jumper input 0 to ground by connecting the ground test lead to input 0’s test lead. Then send the following command to Hydra Series II:

DIO_LEVELS? <CR>

Verify that the returned value as shown on the Host screen = 254.

4.Disconnect input 0 from ground then jumper input 1 to ground. 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 6-7).

TERMINAL GROUNDED

none

0

1

2

3

4

5

6

7

Table 6-7. Digital Input Values

STATE OF DIGITAL INPUTS

inputs 0-7, all HIGH

inputs 1-7 HIGH, input 0 LOW inputs 0,2-7 HIGH, input 1 LOW inputs 0-1 and 3-7 HIGH, input 2 LOW inputs 0-2 and 4-7 HIGH, input 3 LOW inputs 0-3 and 5-7 HIGH, input 4 LOW inputs 0-4 and 6-7 HIGH, input 5 LOW inputs 0-5 and 7 HIGH, input 6 LOW inputs 0-6 HIGH, input 7 LOW

DECIMAL VALUE

255

254

253

251

247

239

223

191

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 2620A/2625A instrument to control the digital line for this test. Refer to Chapter 4 for a description of configuring and operating the Hydra Series II instrument.

1.Ensure that communication parameters (i.e., transmission mode, baud rate, parity, and echo mode) on the 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 0 terminal and the Total (∑) 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.

6-17