SECTION 9. INPUT/OUTPUT INSTRUCTIONS

Pulse duration, initiated by a program control instruction, can be set for each control port (Table 12-2). Instruction 20 does not pulse the port, it only sets the duration. If Instruction 20 is not used to set the duration, the pulse command will result in a 10 ms pulse.

Instruction 20 has two 4 digit parameters. Each digit represents one control port. The code (0-

9)entered as the digit determines what effect command 20 has on the corresponding port.

TABLE 9-5. Port Configuration Option CodesCode Function

0Set port low

1Set port high

2Toggle port

3Pulse duration 1 ms

4Pulse duration 10 ms

5Pulse duration 100 ms

6Pulse duration 1 s

7Configure as output

8Configure as input

9Leave unchanged

Duration of pulse on subsequent pulse port command in Program Control Instruction.

PARAM.

DATA

 

NUMBER

TYPE

DESCRIPTION

01:

4

C8, C7, C6, C5 option

 

 

codes

02:

4

C4, C3, C2, C1 option

 

 

codes

Input locations altered: 0

*** 22 EXCITATION WITH DELAY ***

FUNCTION

This instruction is used in conjunction with others for measuring a response to a timed excitation using the switched analog outputs. It sets the selected excitation output to a specific value, waits for the specified time, then turns off the excitation and waits an additional specified time before continuing execution of the following instruction. Analog power is turned off during delay after excitation to drop power to 3 mA.

If the only requirement is the delay of program execution, the excitation on time (parameter 2) can be set to zero and the off time delay (parameter 3) can be used.

PARAM.

DATA

 

NUMBER

TYPE

DESCRIPTION

01:

2

Excitation channel

 

 

number

02:

4

Delay time in

 

 

hundredths of a

 

 

second that excitation

 

 

is on

03:

4

Delay time in hundredths

 

 

of a second after

 

 

excitation is turned off

04:

FP

Excitation voltage in

 

 

millivolts

Input locations altered:

0

*** 23 BURST MEASUREMENT ***

FUNCTION

Instruction 23 will repeatedly make a voltage measurement on a series of single-ended or differential channels, applying excitation if desired. The measurement units are millivolts prior to scaling. The measurements saved can be those made immediately upon execution of the instruction or grouped around a specified trigger condition. The results of the measurements may be stored in Input Storage or the raw A/D data can be sent out the serial port. The minimum sample time per channel is 1.333 ms (i.e., one channel can be sampled at a maximum rate of 750 Hz).

MEASUREMENT

The voltage measurement must use the fast integration time of 272 µs. Differential measurements are made with a single integration. The noise level on a fast single- ended or a differential measurement with 1 integration is 3 µV RMS. Thus, only the 25 mV and greater voltage ranges are practical (range codes 13-15).

Excitation is always supplied from excitation channel 1. The excitation voltage in millivolts is entered in Parameter 9. If excitation is not desired, enter 0 for Parameter 9.

Three options are available for the first digit in Parameter 4.

0 - Trigger on first measurement channel.

1 - Trigger on Digital Control Port 1.

2 - Trigger on first measurement channel, set Digital Control Port high when trigger is met and low when measurements have finished.

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