FC 229 - Pulse In / Channel

The exception reporting pulse in/channel function code provides addressing, startup, run-time, and failure mode specifications for an individual or redundant pair of pulse input channels on a Harmony I/O block or S800 incremental pulse module. The pulse in/channel function code must reside in the same segment foreign device definition function code 228 to which it is mapped. This function is required for all configured pulse input I/O block channels.

 

NOTES:

1. Function code 229 tunable specifications are not adaptable.

2. Pulse input channels are supported only by the IOR-800 with DP820 or DP840. The DP820 and DP840 are incremental pulse counter I/O modules.

 

 

Outputs:

Blk

Type

Description

N

R

Pulse input value (in specified EUs) with quality.

 

 

 

Specifications:

Spec

Tune

Default

Type

Range

Description

S1

N

Null

String

0 - 32

32-character channel label

S2

N

101

I

xy0, xy1,

xy2, xy3,

xy4, xy5,

or xy6

x=0 or 1

and y=0

Filtering/conversion type:

Conversion type

xy0 - Period. Not supported by IOR-800.

xy1 - Frequency

xy2 - Duration (Not supported by DP820/DP840.)

xy3 - Totalize up

xy4 - Totalize down

xy5 - Totalize up with reset on high alarm limit (Resets to start value + overrun when high alarm is exceeded.)

xy6 - Totalize down with reset on low alarm limit (Resets to start value + overrun when low alarm is exceeded.)

y - Rising/falling edge level. For DP820/DP840, it is set to zero.

 

Pulse trigger level:

x0z - Low to high

x1z - High to low

 

Filtering

0yz - Filtering disabled

1yz - Filtering enabled

 

S3

N

0.000

R

Full

Engineering units low value

S4

N

100.000

R

Full

Engineering units high value

S5

N

0

I

0 - 255

Engineering units identifier

S6

Y

100.000

R

Full

Engineering units high alarm

S7

Y

0.000

R

Full

Engineering units low alarm

S8

Y

0.000

R

Full

Engineering units significant change

S9

Y

-5.000

R

Full

Engineering units alarm dead-band. Prevents alarm chattering.  Supersedes S10 in function code 82 when set to a positive value.

S103

N

0.000

R

Full

Expected channel low value.

Expected low frequency value (Hertz) (S2=x0) or

Expected low period value (Seconds) (S2=x1) or

Expected low duration value (Counts) (S2=x2)

Expected low count limit (Counts) (S2=x3/4/5/6)

S113

N

5000.000

R

Full

Expected channel high value.

Expected high frequency value (Hertz) (S2=x0) or

Expected high period value (Seconds) (S2=x1) or

Expected high duration value (Counts) (S2=x2)

Expected high count limit (Counts) (S2=x3/4/5/6)

S12

N

0

R

Full

Engineering units start value.

S13

N

2

I

Note 1

Block address of Reset.

0 - Continue

1 - Reset to start value

S14

N

2

I

Note 1

Block address of Hold.

0 - Continue

1 - Hold accumulated value

S15

N

0

B

0 or 1

Normal input/undefined.

S16

Y

0.000

R

Full

Override value.

S172

Y

0

B

0 or 1

Override enable.

S18

N

2

I

Note 1

Block address of simulation value.

S192

Y

0

I

0 or 1

Simulation enable.

S202

Y

0

B

0 or 1

Status error inhibit.

S21

Y

9.2E18

R

Full

Redundant input deviation limit.

S22

Y

0.000

R

Full

Reserved for future use.

S23

N

Null

String

0 - 32

32-character channel configuration parameter.

S24

N

0

I

Full

Reserved for future use.

S254

N

2

I

Note 1

Block address of next element of the foreign device.

S26

N

2

I

Full

Spare

S27

N

0.000

R

Full

Spare

S28

Y

0.000

R

Full

Spare

S29

Y

0.000

R

Full

Spare

S30

Y

0.000

R

Full

Spare

S31

N

0

I

Full

Spare

S32

N

2

I

Full

Spare

 

NOTES:

  1. Maximum values are:9,998 for the BRC-100, BRC-200, BRC-300, and IMMFP11/12,  31,998 for the BRC-400 and HAC

  2. Specification value active state is permitted to operate only when S11 of the gateway function code 227is enabled.

  3. The frequency/period/duration range and offset are calculated from the S10 and S11. Greater specified range settings allow for greater/lesser frequency, period, and duration measurements at the trade-off of lesser/greater precision of measurement. The range and offset values specified are translated and used by pulse input hardware to program its hardware specific measurement ranges and offsets.

  4. Links to the next element of the foreign device definition (228) function block.

 

 

 

229.1   Explanation

 

229.1.1  Specifications

 

S1

(Channel label) Optional channel identifier. It is not required to be configured and can be null. The channel label can be up

to 32 characters long.

 

S2

(Conversion type) The conversion type is specified as a three digit number of the following format:

 

FLT

 

where:

 

F

Filtering

(1=yes, 0=no)

 

Filtering enables pulse input hardware signal filtering. It is typically enabled, but may be disabled for low voltage/current type pulse input applications in order to allow for higher frequency pulse input signals where special EMI protection is provided for the inputs. It is recommended to be set.

 

L

Pulse trigger level

(0=low to high transitions,  1=high to low transitions)

 

Pulse trigger level selection is not supported by the DP820/DP840 S800 modules. Set to zero.

 

T

Type

0 = Period. Same functionality as function code 102. Period functionality is not supported by IOR-800.

1 = Frequency. Same functionality as function code 103.

2 = Duration. Same functionality as function code 109. (Not supported by DP820/DP840).

3 = Totalize up. Same functionality as function code 104 with S5=0 and S8=0.

4 = Totalize down. Same functionality as function code 104 with S5=1 and S8=0.

5 = Totalize Up with reset on high alarm limit. (Same functionality as function code 104 with S5=0 and S8=1). Resets to start value plus overrun when high alarm is exceeded.

6 = Totalize Down with reset on low alarm limit. (Same functionality as function code 104 with S5=1 and S8=1). Resets to start value plus overrun when low alarm is exceeded.

 

  • In Period mode, the module measures the time between consecutive pulses. The total measurement range is 5 microseconds (filtered) or 6.67 microseconds (unfiltered) to 2.5 seconds with High and Low alarms. Positive pulses can be measured. The time measured is the time between the rising edge of a pulse to the rising edge of the next pulse (rising edge detection). The resolution of the period measurement depends on the application and is guaranteed to be have a maximum absolute frequency error of 1.64 parts/million. If no pulses are detected, then the last measured value is held until a loss of signal time period expires.

  • In Frequency mode, the DP820/DP840 counts the number of input pulses or cycles that occur in a fixed preset time period on a channel. The total measurement range is 0.25 Hz to 200 kilohertz (filtered) or 1500 kilohertz (unfiltered) with High and Low alarms for the DP820 and 0.5 Hz to 20 kilohertz (filtered) for the DP840. The DP820/DP840 reads the value and provides it to the controller when the controller requests an update (S2 of function code 82 –target period of segment). The resolution of the frequency measurement depends on the selected measurement interval. If no pulses are detected, then the last measured value is held until a loss of signal time period expires.

 

NOTE: For Period and Frequency modes, the DP820 supports a fixed 4.3 second loss of signal detection period (DP840 = 3 seconds). If no incoming pulses are detected during the 4.3 second time span, the overflow status is set. If there are other problems with the input (such as a frequency period not being able to be determined), the transducer power failure (POWR) status will be generated to HSIs so that a reference error condition will be indicated.

 

  • In Totalize mode, the DP820/DP840 counts the total number of pulses of a digital input up to its expected channelhigh value (S11) with hold and reset flags or until the controller resets the counter.

 

 

 

S3

(Engineering units low value) Defines the low limit of the input’s range in engineering units.

 

S4

(Engineering units low value) Defines the high limit of the input’s range in engineering units.

 

S5

(Engineering unit identifier) identifies the engineering units associated with the input value.

 

S6

(Engineering units high alarm) An alarm will be generated when the input equals or exceeds this high limit.

 

S7

(Engineering units low alarm) An alarm will be generated when the input equals or is less than this low limit.

 

S8

(Engineering units significant change) The change in input allowed before the changed value is reported to a console or open access system.

 

S9

(Engineering units alarm dead-band) Alarm deadband for the high/low alarm. Alarm deadbands prevent excessive alarm exception reports when values are hovering around the alarm limit. Supersedes specification S10 of function code 82 for this function code 229 block when set to a positive value.

 

S10

(Expected channel low value) The expected low limit of the pulse input channel physical channel as expressed in units (Hertz, Seconds, or Counts) appropriate to the Conversion Mode (S2).

 

S11

(Expected channel high value) The expected high limit of the pulse input channel physical channel as expressed in units (Hertz, Seconds, or Counts) appropriate to the conversion mode (S2).

 

Specifications S10 and S11 define the expected field input signal range of the channel and are utilized in the calculation of the final engineering unit value as follows:

 

Engineering unit output = ((channel value - S10) * (S4-S3) / (S11-S10)) + S3

 

S10 and S11 are also utilized by the pulse-input hardware to configure the optimal frequency/period/duration measurement range to achieve the maximum resolution in the measurement.

 

 

NOTES:

To utilize the pulse in/channel to produce absolute totalization counts, the S10 and S11 specifications can be set to the same values as the S3 and S4 specifications respectively.

To utilize the pulse in/channel to produce an unbounded maximum totalization count, set both S11 and S4 to the maximum possible floating point value.

 

S12

(Engineering Unit Start value) Defines the initial totalization count value on startup and function code reset (<S13>=1).  The value of the count is equal to specification S12 plus the alarm overrun after an alarm if the conversion mode (S2) is set to 5 or 6.

 

NOTE: Alarm overrun is the current total count reset to the difference between the counter and the alarm limit. This allows the pulse in / channel function code (229) to correctly detect the next alarm without losing track of the true counts.

 

S13

(Block address of reset) Block address of the reset flag that is applicable only to the totalization conversion modes 3 through 6 in S2.

0 = Continue totalization (normal).

1 = Reset totalization count to start value (S12).

 

S14

(Block address of hold) Specification S14 is the block address of the accumulated total hold flag and is applicable only for the totalization conversion modes 3 through 6 in S2.

0 = Continue totalization (normal).

1 = Hold accumulated total.

 

NOTE: The reset and hold inputs function in the NORMAL operating mode only and do not supersede OVERRIDE, UNDEFINED, or SIMULATION mode operation.

 

S15

(Normal input/undefined) A value of 0 selects normal input from standard I/O. A value of 1 puts the channel into an undefined state which will not affect the channel status. Specifications S17 and S19 take precedence over S15 when S15 = 0, but not when S15 = 1.

0 = Normal

1 = Undefined

 

S16

(Override value) The channel input value is over-ridden with this value if the override enable (S17) is set to 1.

 

S17

(Override enable) A value of 0 disables override for this channel. A value of 1 enables override in this channel. If enabled, override will take precedence over normal input and simulation. Specification S11 of the gateway (function code 227) must reference a boolean output that is set to 1 to permit this operation.

0 = Disabled

1 = Enabled

 

S18

(Block address of simulation value) The channel input value is simulated with this block input when simulation is enabled (S19 = 1).

 

S19

(Simulation enable) A value of 0 disables simulation for this channel. A value of 1 enables simulation for this channel and receives its input from S18. Simulation has precedence over S15 normal input, but not S17 override. Specifications S11 of the gateway function code 227 must reference a boolean output set to a 1 to permit this operation. Otherwise, it is ignored.

0 = Disabled

1 = Enabled

 

S20

(Status error inhibit) Inhibits this channel’s I/O error contribution to BRC-100 controller status. Specification S11 of the

gateway function code 227 must reference a Boolean output with a value of 1 to permit this operation. Otherwise, it is

ignored.

0 = No

1 = Yes

 

S21

(Redundant input deviation limit) In NORMAL mode (S15=0,S17=0,S19=0), the redundant input deviation limit specifies the maximum deviation permitted between redundant pulse input channels. This only applies when both inputs are good quality. When the redundant inputs are outside the deviation limit, they will both be considered in error (function block output quality set to BAD, SUSP flag set in the exception report, and the LIO error bit set in the BRC-100 controller status).

 

In OVERRIDE mode (S15=0,S17=1,S19=X), the redundant input deviation limit assumes the meaning of the override value deviation limit and thus specifies the maximum deviation permitted between the primary pulse input channel and the override value (S16). The pulse input channel value is first converted as specified in S2 before being compared against the override value. If the converted pulse input channel value and the override value are outside the limit, the state of the input channel is considered suspect (SUSP set in the exception report, but no LIO error set in the BRC-100 controller status) since a bump in the block output value will occur upon exiting the OVERRIDE mode.

 

In SIMULATION mode (S15=0,S17=0,S19=1), the redundant input deviation limit assumes the meaning of the simulated value deviation limit and thus specifies the maximum deviation permitted between the primary pulse input channel and the simulated value (<S18>). The pulse input channel value is first converted as specified in S2 before being compared against the simulated value. If the converted pulse input channel value and the simulated value are outside the limit, the state of the input channel is considered suspect (SUSP set in the exception report, but no LIO error is set in the BRC-100 controller status) since a bump in the block output value will occur upon exiting the SIMULATION mode.

 

S22

Reserved.

 

S23

(Foreign device configuration parameters) A string data type containing configuration information specific to the pulse input channel of a foreign device. Presently there are two possible configuration parameters for use with the DP840 module only. Refer to the following table for more information.

NOTE: 1. Default if parameter is not specified.

 

S24

Reserved.

 

S25

(Block address of next element of the foreign device) This specification is the link to the next element of the foreign device definition function code 228. The default value indicates that this block is the last element.

 

S26 through S32

Spare.

 

 

229.1.2  Outputs

 

N

Pulse input value (in specified EUs) with quality and alarm.

 

 

229.2   Application

 

The design of the foreign device (function code 228) and channel (function codes 222 / 225 / 229) layout used in the function code layer is shown in Figure 229-1). The DP820 accepts RS422, 5V, 12V, 24V and 13 mA transducer signal levels. Only the input to the channel A input needs to be configured; the B input is tied to ground. The ST and DI inputs are also tied low.  The DO output does not need to be physically configured.

 

The control logic drawing format for the DP840 is similar to that shown for the DP820, but it may have as many as eight FC 229 blocks chained to the FC 228, whereas the DP820 has at most two channels. The DP840 module supports Namur, 12 V and 24 V transducers. The specific type of transducer used with the DP840 can be specified as part of the FC 228 configuration parameters.