Flowserve 400MD Logix - Manual (Page 98)

STEP SIGNATURE
If a step signature was desired, simply do not select STEP_RAMP in SIG_FLAGS, and then set the STEP_TIME prior to selecting BEGIN_SIG.
Collection of Stored Signature
The collection of the stored signature is accomplished by the host system. It is not part of the device. See host system programming.
A simple utility using National Instruments NIFBUS is available from Flowserve for retrieving a signature file. This file is stored in a text
format that can be imported into other programs for plotting and analysis.
Contact Flowserve for more details.
Retrieve a Signature
After a signature has been run the data is stored on the Logix 3400MD device. Because of the amount of data in a signature it has to be
retrieved from the device. To retrieve this data it is recommended that you use the valvesight DTM. However you can also retrieve the raw
data view it in the parameters XDTB_TECH.SIG_DATA1 – SIG_DATA26. To retrieve this data using the parameters you can simply write a
non zero value to the parameter XDTB_MAIN.SIG_INDEX. When you do this you will see this parameter start changing and the signature
data can then be viewed in the signature parameters. This procedure may take the device several minutes to complete.
The data will be formatted in following order:
Command
Position
Spool Command
Hall Position in Percent
Port 1 Pressure in Percent
Port 2 Pressure in Percent
Future Use
10.15 Logix 3400MD Function Block Execution Times
XDTB_TECH_BLOCK 20 mS
Logix 3400MD Digital Positioner LGENIM3405-02 11/13
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