Fluke 2625A, 2620A user manual Mx+B Scaling, B to define the scaling values

2620A, 2625A

Users Manual

At any Configuration Reset (power up Cor computer interface *RST), alarm limits on channels 4 through 20 are assigned to Digital I/O lines 4 through 7 in the "ORed" pattern shown in Table 3-8. These assignments can be changed via the Computer Interface. Each limit (Sor T) for a channel can be assigned to any one digital output.

Table 3-8. Initial Alarm Assignments, Digital I/O Lines 4 Through 7

Digital I/O Line

Assigned to Channels

(Appropriate channels are OR’ed to drive each I/O line.)

4

4

8

12

16

20

5

5

9

13

17

6

6

10

14

18

7

7

11

15

19

All Digital I/O lines are set high (non-active) whenever power is cycled. These lines remain high until a new scan detects an alarm condition on an assigned limit or until a new Computer Interface command is received.

Note

Measurements taken with the Monitor function do not affect the digital outputs.

At the completion of a scan, an alarm condition sets the assigned digital output to a logic 0 (low) state. The digital output returns to a logic 1 (high) state when all assigned alarm conditions are cleared. Note that digital outputs for alarms are updated only at the end of each scan. This technique prevents unnecessary toggling of the digital lines during a scan.

Mx+B Scaling

Any analog input channel (0 through 20) can be assigned scaling ("M" and "B") values that are applied to subsequent measurements of that channel. Scaling values can be set via the front panel or over a computer interface.

The "M" value is used as a multiplier of the actual reading; the "B" value is then added in the same units as the resultant. If no scaling values are specified for a channel, the Configuration Reset values of 1 ("M") and 0 ("B") are used, leaving the measurement reading unaltered.

In the Inactive Mode, the "Mx+B" annunciator lights to indicate that an M value other than 1 and/or a B value other than 0 has been specified for the displayed channel. When a measurement is displayed for a channel so configured, no measurement units ("Ω", "V", etc.) are shown.

Note

If you press Bfor a channel that is OFF, an error beep will result. Always use Fto define the channel’s measurement function before using

Bto define the scaling values.

You can familiarize yourself with the Mx+B setup procedure by pressing B. Then press Ea few times to cycle through the elements of the scaling values. If only

Eis pressed, no changes are introduced. Note that the scaling value element that can

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