Smart Pressure Transmitter

TTC             SMART PRESSURE TRANSMITTER            LAB #X

                                                HONEYWELL ST3000

OBJECTIVES

1.         Introduce smart temperature transmitters and smart field communicator functions and operations.

2.         Calculate and validate smart temperature transmitter output responses.

3.         Configure the smart temperature transmitter for both thermocouple and RTD sensors.

4.         Perform a 4-20 mA trim (i.e. "D to A" calibration) on a smart temperature transmitter.

5.         Calibrate the input section (i.e. "A to D" calibration) of a smart temperature transmitter.

6.         Perform a cloning procedure.

EQUIPMENT

- Honeywell ST3000 Smart Pressure Transmitter                  - 250 Ohm Resistor

- Honeywell Smart Field Communicator                                   - 24 Volt Power Supply

- Druck 605 DPI (Digital Pressure Indicator)                           - Fluke 8060A DMM                                                                     

PRE-LAB

1.         Explain the difference between a smart pressure transmitter and a conventional pressure transmitter.

2.         Explain what is meant by “configuring” a smart pressure transmitter versus "calibrating" a smart pressure transmitter.

PROCEDURE

1.         Connect the Honeywell ST3000 Smart Pressure Transmitter to the bench 24 volt power supply.  Include in the loop a 250 resistor (necessary for digital communication) and a Fluke DMM.  Connect the Honeywell Smart Field Communicator (SFC) to the transmitter's 4-20 mA measurement loop terminals:  red to positive and black to negative.  Refer to the drawing shown below:

2.         Connect the Druck 605 DPI pressure source to the high (H) side of the transmitter, making sure connections are tight.

3.         Configure the ST3000 Smart Pressure Transmitter for the following:

            Damping Time                     =          1.12 seconds

            Units                                      =          “ W.C.                       

            Lower Range Value            =          0 “ W.C.

            Upper Range Value            =          100 ” W.C.

            Output                                   =          linear

                       

            The first thing that you must do is transfer the transmitter's configuration information into the Working Memory of the SFC..  To do this, turn the SFC on, then press the [ID] key. 

           

            The display will look similar to the one shown below:

           

           

            To adjust the damping time, follow the procedure on page 53 of the STS103 operating guide.

            To adjust the units in which to display values, follow the procedure on page 54 of the STS103 operating guide.

            To key in the LRV and URV, follow the procedure on pages 58 and 59 of the STS103 operating guide.

3.         (continued)

For the previous elements, any changes that you make to the Working Memory of the SFC are also made (sent) to the Working Memory of the transmitter.

           

            The remaining element (output info) is only accessible in the configuration mode.  To activate this mode, press [CONF], then press [ENTER].  Then follow the procedure on pages 62 and 63 of the STS103 operating guide to change the output type to linear.

            Note, in configuration mode, after you have changed the above elements as required, these changes are only made to the SFC Working Memory.  In order to make changes to the actual transmitter (XMTR) Working Memory, the SFC Working Memory must be transferred to the XMTR Working Memory.  Follow the procedure carefully.

            Note, after transferring the SFC memory to the XMTR memory, check the LRV and URV to see if they are still correct (sometimes these values will change if the probe type is changed!).  Correct if necessary.

4.         Quickly verify the configuration by measuring the pressures indicated in table 1. Record all required information in table 1.  (Note, reference pressure measurement is the pressure as indicated by the Druck 605 DPI pressure source.)

           

            Note, it is possible to display the pressure (as measured by the transmitter) on the SFC display.  Press [SHIFT], then press [INPUT].  Pressure is updated once every 6 seconds.

            Note, it is possible to display the transmitter output on the SFC display.  Press [OUTPUT].  Transmitter output is updated once every 6 seconds.

            Note, for table 1, pressure is to be calculated based on the mA signal as measured and indicated by the DMM.

5.         With Honeywell Smart Transmitters, it is possible to perform a 4-20 mA trim (i.e. "D to A" calibration).  If this procedure is to be performed, it is important that the transmitter output be measured with a very accurate ammeter.  We will use the Fluke 8060A to measure the current output ... however, a more accurate meter should be used!

            Prior to performing this calibration, record the current as indicated by the Fluke at 0%, 25%, 50%, 75% and 100%.  Record your observations in table 3.  Follow the procedure "Using a Smart Transmitter as a Current Source" on pages 43 and 44 of the STS103 operating guide.

            To do a DAC calibration, follow the procedure on pages 64 to 66 of the STS103 operating guide.

            After performing the DAC calibration, record the current as indicated by the Fluke at 0%, 25%, 50%, 75% and 100%.  Record your observations in table 3.  Follow the procedure "Using a Smart Transmitter as a Current Source" on pages 43 and 44 of the STS103 operating guide.

6.         With Honeywell Smart Transmitters, it is also possible to calibrate the input section of the transmitter (i.e. "A to D" calibration).  If this procedure is to be performed, it is important that the transmitter input be simulated with a very accurate device. In this step, we will use a Druck 605 DPI as the pressure source ... however, a more accurate device should be used!

            Prior to performing the sensor trim, ensure that the transmitter is still configured for a pressure range of 0 psig to 100 “W.C. (keypad method), then record the pressure as indicated by the Honeywell communicator (press [SHIFT], then press [INPUT]) when simulating pressures of 0 “ W.C., 25 “ W.C., 50  “ W.C., 75  “ W.C. and 100  “ W.C..  Record your observations in table 3.

            Honeywell has chosen not to show the user how to perform an ADC calibration in it’s STS103 manual.  The procedure is summarized below (two point calibration):

(a)       Simulate 0 “ W.C. with the Druck 605 DPI, then press [LRV] key, display should indicate 0 “ W.C., then press [CORRECT] key, then press [YES] key.  The display should now say "LRV CORRECTED", the transmitter output should be exactly 4 mA, and the displayed pressure (as indicated by the Honeywell communicator) should be exactly 0 “ W.C. (press [SHIFT], then press [INPUT]).

(b)       Simulate 100  “ W.C. with the Druck 605 DPI, then press [URV] key, display should indicate 100  “ W.C., then press [CORRECT] key, then press [YES] key.  The display should now say "URV CORRECTED", the transmitter output should be exactly 20 mA, and the displayed pressure (as indicated by the Honeywell communicator) should be exactly 100  “ W.C. (press [SHIFT], then press [INPUT]).

            After performing the ADC calibration, record the pressure as indicated by the Honeywell communicator (press [SHIFT], then press [INPUT]) when simulating pressures of 0 “ W.C., 25 “ W.C., 50  “ W.C., 75  “ W.C. and 100  “ W.C..  Record your observations in table 3.

7.         Now that you have performed a 4-20 mA trim and a sensor trim, repeat step 4.  Record all required information in table 4.  You should find that you now have less error due to the "trims".

          Note, again, pressure is to be calculated based on the mA signal as measured and indicated by the DMM.

8.         Rerange the ST3000 by using the applied pressure input source method and the STS103 SFC (page 60 and 61 of the STS103 operating guide).  The required pressure range is 5 to 20 kPa.  Use the Druck 605 DPI as the pressure source. 

           

            Please note that, after reranging with the pressure input source method, it is possible that that the 4 to 20 mA output signal will correspond correctly with the pressure source, yet the pressure as indicated by the STS103 SFC displays a slightly different value than the pressure source.  Since you have performed a sensor trim prior to reranging with the pressure input source method, the above stated condition should not exist.

           

9.         After reranging using the pressure input source method, quickly verify the configuration by measuring the pressures indicated in table 5. Record all required information in table 5.  (Note, reference pressure measurement is the pressure as indicated by the Druck 605 DPI.) 

          Note, for table 5, pressure is to be calculated based on the mA signal as measured and indicated by the DMM.

10.       Using the "RESET CORRECTS" , return the Honeywell ST3000 Smart Pressure Transmitter to it's factory calibration.   The procedure is outlined on page 38 of the STS103 operating guide.

11.       The Hold Memory of the SFC can be used for cloning, i.e. downloading information from one transmitter and uploading the same information to a number of others.  The Hold Memory is also useful for replacing a damaged transmitter with a spare. 

            Perform a cloning procedure as follows:

(a)       Copy the transmitter data base into the SFC Hold Memory by pressing the [SAVE] key, then [ENTER] key.

                       

(b)       Copy the contents of the SFC Hold Memory back into the same transmitter (normally not the same transmitter) by pressing the

            [RE-STORE] key, then [ENTER] key.

                       

12.       With Honeywell smart transmitters, when changes are made to the transmitter configuration and calibration, these changes are only made to the Working Memory of the transmitter.  Prior to disconnecting the SFC from the transmitter, it is necessary to tell the transmitter to store all of the changes into the transmitters non-volatile memory.  Update the non-volatile memory by pressing the [SHIFT] key, then [NON-VOL] key.

           

TTC                                       RESULTS                                      LAB #X

NAME:          _______________________________              DATE: __________________

LAB PARTNER:     _____________________________      CLASS: _________________

Pre-Lab

Signature:    ________________________

Difference between a smart pressure transmitter and a conventional analog pressure transmitter (pre-lab Q#1):

What is meant by "configuring" versus "calibrating" (pre-lab Q#2):

           
Completion of table 1 (keypad method)(step 4):

Input (“ W. C.)	Measured Loop Current (DMM, mA)	Smart Tx Pressure (“ W.C.)	Error (“ W.C)
0.00
25.00
50.00
75.00
100.00

                                                            Table 1

Note, for table 1, pressure is to be calculated based on the mA signal as measured and indicated by the DMM.

"D to A" calibration (step 5):

Before			After
Output Setting (%)	Expected Current (mA)	Actual Current (mA)	Output Setting (%)	Expected Current (mA)	Actual Current (mA)
0	4		0	4
25	8		25	8
50	12		50	12
75	16		75	16
100	20		100	20

                                                          Table 2

"A to D" calibration (step 6):

Before			After
Simulated Input Setting (“ W.C.)	Expected Pressure Display (“ W.C.)	Actual Pressure Display (“ W.C.)	Simulated Input Setting (“ W.C.)	Expected Pressure Display (“ W.C.)	Actual Pressure Display (“ W.C.)
0	0		0	0
25	25		25	25
50	50		50	50
75	75		75	75
100	100		100	100

                                                          Table 3

Completion of table 4 (keypad method)(step 7):

Input (“ W.C.)	Measured Loop Current (DMM, mA)	Smart Tx Pressure (“ W.C.)	Error (“ W.C.)
0.00
25.00
50.00
75.00
100.00

                                                            Table 4

Note, for table 4, pressure is to be calculated based on the mA signal as measured and indicated by the DMM.

Completion of table 5 (pressure input source method)(step 9):

Input (kPa)	Measured Loop Current (DMM, mA)	Smart Tx Pressure (kPa)	Error (kPa)
5.00
10.00
15.00
20.00

                                                            Table 5

Note, for table 5, pressure is to be calculated based on the mA signal as measured and indicated by the DMM.

Reference : NAIT Edmonton CA