GE IC697VAL348 DAC Zero Offset and Gain Calibration, Channel Offest Pot, Gain Pot, P3 Connector

2

DAC Zero Offset and Gain Calibration

Note

This procedure assumes that the offset binary coding jumper (JA) is selected.

1.Remove power from the Digital-to-Analog Converter Board.

2.Remove any cable connected to the P3 connector.

3.Remove the Digital-to-Analog Converter Board from the chassis assembly and install a VMEbus Extender board in its place.

4.Install the Digital-to-Analog Converter Board onto the VMEbus Extender board.

5.Apply power to the module and allow 15 minutes for Temperature Stabilization before making any measurements.

6.Using the IMMEDIATE UPDATE MODE write digital code 4100 HEX to the CSR location XXXX0070. This HEX code is the Control Word for output to the Digital-to- Analog Converter Board’s P3 connector.

7.Write 8000 HEX to each of the eight DAC channels at addresses XXXX0060 through XXXX006E.

8.Using a 6-digit multimeter, monitor each DAC output at the P3 connector. Connect the negative lead to connector P3 pin C2. Adjust each DAC's offset potentiometer for a voltage of 0.0000 ±60 µV. Refer to Table 2-4 below and Figure 2-6 on page 2-16 for the Potentiometer Location and P3 connector pin for each channel.

Table 2-4. Digital-to-Analog Converter Board Calibration Table

Channel

1

2

3

4

5

6

7

8

Offest Pot

R23

R19

R31

R27

R3

R7

R15

R11

Gain Pot

R21

R17

R29

R25

R1

R5

R13

R9

P3 Connector

A2

A3

A4

A5

A6

A7

A8

A9

9.Repeat Step 7 using digital code FFFF HEX.

10.Using the multimeter, monitor each DAC output at the P3 connector. Connect the negative lead to connector P3 pin C2. Adjust each DAC's gain potentiometer for a voltage of 9.99969 ±60 µV. Refer to Table 2-4 above and Figure 2-6 on page 2-16 for the Potentiometer Location and P3 connector pin for each channel.

11.Remove extender and re-install board into the chassis. Calibration completed.

GFK-2059 Chapter 2 Configuration and Installation 2-15