FC 109 - Pulse Input / Duration

The pulse input/duration function code interfaces a controller to a selected channel of an IMDSM04 Pulse Input Slave Module. Function code 109 specifies the duration of the input pulses. The IMDSM04 module conditions, converts and processes pulse inputs into analog signals. It has eight input channels whose inputs can be processed in three modes (period, frequency and totalization). Function codes 102, 103 and 104 process signals in the period, frequency and totalization modes, respectively. Each input channel must have one and only one pulse input block configured.

 

Outputs:

Blk

Type

Description

N

R

Pulse duration (seconds) X gain

N+1

B

Pulse duration high alarm:

0 = no alarm

1 = high alarm

N+2

B

Pulse duration low alarm:

0 = no alarm

1 = low alarm

N+3

B

I/O module communication status:

0 = good

1 = bad

 

 

Specifications:

Spec

Tune

Default

Type

Range

Description

S1

N

0

I

0 - 63

Expander bus I/O module address of IMDSM04

S2

N

1

I

1 - 8

Selected channel

S3

N

0

B

0 or 1

Pulse trigger level (start of duration measurements):

0 = low to high transitions

1 = high to low transitions

S4

N

1

I

1 - 6

Expected pulse duration range:

1 = 0.1 msec to 6.55 secs

2 = 1.0 msec to 65.5 secs

3 = 10.0 msecs to 655.4 secs

4 = 0.1 sec to 6,553.5 secs

5 = 1.0 sec to 65,535 secs

6 = 10.0 secs to 655,350 secs

S5

Y

1.000

R

Full

Gain

S6

Y

9.2E18

R

Full

High alarm value

S7

Y

-9.2E18

R

Full

Low alarm value

S8

Y

0.000

R

Full

Reserved

 

 

 

109.1  Explanation

 

The pulse input/duration function code specifies an expected pulse duration. It outputs the duration (multiplied by a gain, S5) of the last pulse to occur during the configured pulse duration range S4. If no pulse occurs, the output remains at the last non-zero value. It provides alarms if the pulse input exceeds the selected high and low limits. The trigger transition level (begin count on low-to-high or high-to-low transition) and gain for the output can be selected.

 

 

109.1.1  Specifications

 

S1 - SLVADR

Expander bus I/O module address of IMDSM04 module. Valid addresses are zero to 63.

 

S2 - CHNL

Identifies the input channel being monitored. IMDSM04 modules have eight input channels. Refer to the IMDSM04 Pulse Input Module product instruction to identify the channel associated with each input.

 

S3 - PTRIG

Defines the type of signal transition that triggers the counter response.

0 = response on low to high transitions

1 = response on high to low transitions

 

S4 - RANGE

Defines the expected range of the pulse duration. The ranges are:

1 = 0.1 millisecond to 6.55 seconds

2 = 1.0 millisecond to 65.5 seconds

3 = 10.0 milliseconds to 655.4 seconds

4 = 0.1 second to 6,553.4 seconds

5 = 1.0 second to 65,535 seconds

6 = 10.0 seconds to 655,350 seconds

 

If the input pulse duration is greater than the expected range, output block N freezes with the last valid pulse duration and

the I/O module communication status changes to a one (bad).

 

S5 - K

Defines the gain multiplier: the value that scales the output to a useful value for control purposes.

 

S6 - HALRM

Pulse duration high alarm. When the measured pulse duration exceeds this value, output N+1 equals one.

 

S7 - LALRM

Pulse duration low alarm value. When the measured pulse duration is less than this value, output N+2 equals one.

 

S8

Reserved.

 

 

109.1.2  Outputs

 

N

Pulse duration (seconds) times the gain.

 

N+1

Pulse duration high alarm indicator.

0 = no alarm

1 = pulse duration has exceeded high alarm limit set by S6

 

N+2

Pulse duration low alarm indicator.

0 = no alarm

1 = pulse duration is shorter than low alarm limit set by S7

 

N+3

I/O module communication status.

0 = good

1 = bad

 

I/O module is marked bad if:

• There is an illegal or no I/O module response.

• No pulses have been received yet.

• The pulse duration exceeds the expected range