FC 217 - Enhanced Calibration Command

The enhanced calibration command function code (ECC) permits calibration and diagnostic testing of the IMASI13 universal analog input module.

 

The operator initiates, guides and terminates a calibration or diagnostic sequence with this enhanced calibration command function code. Commands are entered by tuning this block. The status of the command may be determined by examining S1 after the tune operation is completed. If S1 is zero after tuning function code 217, an error has occurred.

 

Before beginning calibration, each channel must be configured with one function code 216 and the calibration type defined in S4 of function code 217 must be consistent with the input signal defined in S4 of function code 216.

 

A detailed description of any command errors is provided as an output (N+4) to this function block. This output reflects the status of the most recently issued calibration command.

 

Errors encountered during calibration of a particular channel are also reported as an output (N+1) to this function block. This output reflects the status for the channel referenced in the most recent command. For more information, refer to the IMASI13 Isolated Analog Input Module instruction.

 

 

 

Outputs:

Blk

Type

Description

N

R

Uncorrected value of input signal

N+1

R

Channel calibration status

N+2

R

Custom gain adjustment

N+3

R

Custom offset adjustment

N+4

R

Calibration Command Status

 

 

 

Specifications:

Spec

Tune

Default

Type

Range

Description

S1

Y

0

I

0 - 255

Calibration operation code

S2

Y

0

I

Note 1

Block address of function code 215 used to configure input module

S3

Y

0

I

Full

Input module channel number

S4

Y

0

I

0 - 2

Calibration type:

0 = low level (millivolt, thermocouple)

1 = high level

2 = RTD

S5

Y

0.000

R

Full

Calibration parameter 1

S6

Y

0.000

R

Full

Calibration parameter 2

S7

N

0

I

Full

Spare

S8

N

0.000

R

Full

Spare

 

NOTE:

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

 

 

 

217.1.1  Specifications

 

S1

Tuned to the proper command code for the calibration operation to be performed. Specification S1 is returned as a zero in

the event of a calibration command error, and must be changed before sending another calibration command to the

module. Specification S1 is unchanged if calibration command processing is successful.

 

  1. Disable point - removes a channel from normal input scan processing. A point must be disabled before performing a point calibration command to prevent calibration related data from being interpreted as process data by the rest of the system. Calibration should only be performed using precision voltage or resistance sources applied at the terminal blocks. In addition, before a point can be successfully disabled, the point must first be configured with a function code 216.

  2. Perform point calibration using external reference - the precision voltage or resistance source must be connected prior to issuing this command. Before a successful point calibration can be implemented, the calibration type defined in S4 of function code 217 must be consistent with the input signal type defined in S4 of function code 216. Refer to the specific examples under the S4 explanations in this function code. Also refer to the calibration section of the IMASI13 product instruction.

  3. Enable point - terminates the field calibration sequence for an input channel type. A point must be enabled before normal input processing can occur. Selected gain and offset values will be reset to 1.0 and 0.0, respectively, if a successful calibration has been performed.

  4. Point escape - resets (clears) calibration point information for a particular channel in the middle of a calibration sequence. It clears only the point data. This allows a restart of a calibration procedure for the specified channel. The point escape command does not enable the channel.

  5. Set custom gain and offset adjustment - allows a linear adjustment factor to be entered. This will be applied to the input signal after all drift and nonlinearity corrections, but before conversion to engineering units. This value is applied to low level, high level and resistance values.

  6. Reset custom gain and offset adjustment - cancels any previously entered custom gain and offset adjustment for the specified input channel type. After issuing this command, the gain for the input channel type is one and the offset is zero.

  7. Display uncorrected point data (percent of positive full scale) - performs no operation other than to update the uncorrected output data value for the specified input channel (block output N of function code 217).

  8. Update point data - causes a new scan of the specified input channel to be performed and the output data value of the block to be updated with the new uncorrected value.

  9. Input module escape command - performs point escape command to all 16 channels and cold junction reference on the IMASI13 module.

  10. Expander bus test command - performs single test of expander bus between the module and the secondary input module. The test verifies transmission, reception and data integrity of messages passed between the module and the secondary input module (intended as an additional diagnostic for the input module bus interface). This operation can be performed with a local or remotely configured IMASI13 module. This test can be performed on-line.

  11. Restore factory calibration command - overwrites the field calibration data in NVRAM with the original factory calibration parameters. This command also resets any values entered by the set custom gain and offset command.

 

 

S2

Identifies the block address of the EASD block (function code 215) that identifies which input module is referred to by the

command specified in S1.

 

S3

Identifies the module input channel number of the applicable command specified in S1.

 

S4

Identifies the type of calibration performed.

0 = low level (millivolt, thermocouple)

1 = high level

2 = RTD

 

For calibration of the IMASI01 or IMASI13 module, the calibration type defined in S4 of function code 217 must be consistent with the input signal type defined in S4 of function code 216. Consider the following examples.

 

Example 1

If calibrating a channel for millivolts or thermocouples, then S4 of function code 217 must be set to 0 and S4 of function code 216 must be set to any one of the millivolt or thermocouple input types. In this case, S4 of function code 216 must be within the following:

 

x01 > S4 < x20

         or

x60 > S4 < x99

 

Example 2

If calibrating a channel for high level voltage, then S4 of function code 217 must be set to 1 and S4 of function code 216 must be set to one of the high level voltage ranges (4 to 20 mA is considered high level input type). In this case, ffunction code 216 should be within the following:

x40 > S4 < 60

       or

S4 = x99

 

Example 3

If calibrating a channel for RTD mode, then S4 of function code 217 must be set to 2 and S4 of function code 216 must be set to any one of the RTD types. In this case, S4 of ffunction code 216 should be within the following range:

 

x20 > S4 < x40

 

 

S5

Used for channel input type calibration and changing the custom gain and offset value. Calibration parameter one provides a real value dependent upon the type of command S1 specifies.

 

When S1 equals two, point calibration, this parameter specifies the true value of the signal applied to the input channel during the calibration operation. Enter an S5 value for each calibration point. Up to 11 points may be identified for adjustment of input channel nonlinearities, resulting in ten linear segments for correction. These calibration points may be applied in any order. The units for the point value are determined by the type of calibration operation specified in S4. For example,

 

Low level = -100 millivolts to +100 millivolts

High level = -10 volts to +10 volts

RTD = 5 ohms to 500 ohms

 

When S1 equals five, specified gain and offset applications, S5 specifies the gain and S6 specifies the offset. When the IMASI13 module is shipped, the default value for gain is set to one and the default value for offset is set to zero. This command (S1 equals five) sets both the gain and offset parameters simultaneously each time it is entered. The gain, or slope, is the linear correction to be applied. Both gain and offset adjustments are changed at one time.

 

S6

Used to specify an offset for the custom gain and offset command (S1 equals five). It provides a real value dependent upon the type of command specified in S1.

 

This parameter specifies the offset of the linear correction to be performed. The units for the offset value are determined by the type of calibration operation specified in S4. For example:

 

Low level = -100 millivolts to +100 millivolts

High level = -10 volts to +10 volts

RTD = 5 ohms to 500 ohms

 

 

 

217.1.2  Outputs

 

N

Uncorrected value of the input signal. This output gives the value of the input signal without any of the calibration, drift, lead wire, or cold junction compensations applied. The raw digitized value is converted to a range of -100 to +100.

 

N+1

Channel calibration status. This output gives the detailed status of the last calibration operation performed on the specified channel.

0 = channel calibration command was successful