HP 34970A Example: Configuring an Alarm on a Digital Input

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

Example: Configuring an Alarm on a Digital Input

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			Data read from port (decimal 146)
1 0 0 0 0 0 0 0			CALC:COMP:DATA command (decimal 128)
			“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 (@<ch_list>)

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

CALCulate:LIMit:UPPer <count>[,(@<ch_list>)]

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

CALCulate:LIMit:UPPer:STATe ON [,(@<ch_list>)]

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