PARAM.

DATA

 

NUM.

TYPE

DESCRIPTION

01:

4

MASK (0-255)

02:

4

INPUT LOCATION TO

 

 

STORE RESULT

Input locations altered:

1

*** 26 TIMER ***

FUNCTION

This instruction will reset a timer or store the elapsed time registered by the timer in seconds in an Input Storage location. Instruction 26 can be used with Program Control Instructions to measure the elapsed time between specific input conditions. There is only one timer and it is common to all tables (e.g., if the timer is reset in Table 1 and later in Table 2, a subsequent instruction in Table 1 to read the timer will store the elapsed time since the timer was reset in Table 2).

Elapsed time is tracked in 0.125 second increments. The maximum interval that can be timed is 8191.875 seconds.

The timer is also reset in response to certain keyboard entries:

1.When tables are changed and compiled with the *0 Mode, the timer is reset automatically.

2.Entering "*6" after changing the program compiles the programs, but does NOT reset the timer.

PARAM.

DATA

 

NUM.

TYPE

DESCRIPTION

01:

4

Input location no. of

 

 

elapsed time in

 

 

seconds (or enter 0 to

 

 

reset)

Input locations altered:

1

(0 if timer is being reset)

*** 27 PERIOD MEASUREMENT ***

FUNCTION

Instruction 27 measures the period (microseconds) of a signal on a single ended input channel. As an option, the frequency of the signal in kHz may be output instead of the period. The specified number of cycles are timed with a resolution of +60 nanoseconds,

SECTION 9. INPUT/OUTPUT INSTRUCTIONS

making the resolution on the period 60 nanoseconds divided by the number of cycles measured. Resolution is reduced by noise and signals with a slow transition through the zero voltage threshold. The "Time out" parameter specifies the maximum length of time the instruction will wait on each repetition for the specified number of cycles. If the cycles have not been counted within this time, -99999 will be loaded into the input location.

Input Frequency Gain Codes

Range

Peak to Peak Volts

Maximum

Code

Required @ Max. Freq.*

Frequency

1

2

mV

8 kHz

2

3

mV

20 kHz

3

12

mV

50 kHz

4

2

V

200 kHz

0x Output period in microseconds

1x Output frequency in kHz where x is range code

* AC voltage; must be centered around CR10 ground.

PARAM.

DATA

 

NUM.

TYPE

DESCRIPTION

01:

2

Repetitions

02:

2

Gain/output option

03:

2

Single-ended input

 

 

channel

04:

4

# Cycles to measure

05:

4

Time out (0.01 sec, at

 

 

least the maximum

 

 

duration of the number

 

 

of cycles specified + 1

 

 

1/2 cycles.)

06:

4

Destination input

 

 

location

07:

FP

Multiplier

08:

FP

Offset

Input locations altered:

1* Repetitions

*** 28 VIBRATING WIRE ***MEASUREMENT

FUNCTION

Excites a vibrating wire sensor with a swept frequency (from low frequency to high), then measures the response period and calculates 1/T2, where T is the period in ms. Excitation is normally provided for before each repetition. As an option, a single excitation can be made prior to all repetitions

9-15