A

B

X-OR

 

 

 

0

0

0

0

1

1

1

0

1

1

1

0

 

 

 

 

 

 

A

B

AND

 

 

 

0

0

0

0

1

0

1

0

0

1

1

1

 

 

 

Chapter 4 Features and Functions

Alarm Limits

x u

Assume that you want to generate an alarm when a binary pattern of “1000” is read on the upper four bits of port 1. Send the following commands to configure the port for an alarm.

CALC:COMP:TYPE EQUAL,(@301)

CALC:COMP:DATA 128,(@301)

CALC:COMP:MASK 240,(@301)

OUTPUT:ALARM2:SOURCE (@301)

CALC:COMP:STATE ON,(@301)

Here are the calculations used to evaluate the alarm (assume that a decimal 146 was read from the port):

Bit 7

Bit 0

 

1 0 0 1 0 0 1 0

 

Pt tw y /wxv”t 8=B0

1 0 0 0 0 0 0 0

 

CALC:COMP:DATA v /wxv”t 89D0

 

 

 

“X-OR” result

0 0 0 1 0 0 1 0

 

1 1 1 1 0 0 0 0

 

CALC:COMP:MASK command (decimal 240)

 

 

 

“AND” result (no alarm generated)

0 0 0 1 0 0 0 0

 

Since the calculations produce a non-zero result (decimal 16), an alarm is not generated in this example.

Remote Interface Operation (Totalizer Channel): To assign the alarm number to report any alarm conditions on the specified totalizer channels, use the following command.

OUTPut:ALARm[1234]:SOURce (@<v“r >)

To configure an alarm on a totalizer channel, specify the desired count as the upper limit using the following command.

CALCulate:LIMit:UPPer <v >[,(@<v“r >)]

To enable the upper limit on the specified totalizer channel, use the following command.

CALCulate:LIMit:UPPer:STATe ON [,(@<v“r >)]

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HP 34970A manual Pt tw y /wxvt 8=B0, Or result, Calccompmask command decimal, Result no alarm generated