Delta Controls 2HTDCAL - Manual (Page 9)

{ACCESS 2}
The (TRIMxxx) functions are used to trim the Lower and Upper Range Values of the analogue to
digital converter (ADC) to an accurately generated, external pressure standard. This is used if the
instrument is found to differ from the site standard, for whatever reason. The command can also
be used to increase the measurement accuracy of a turned down instrument.
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{HIT SAVE} will be displayed, there are two choices :-
[SELECT] or [CHANGE] To abort and return to the {TRIM LRV} menu
[[SELECT]] Press and hold for two seconds to store the ADC offset value,
{SAVED} will be displayed to show that the command is successful.
{TRIM URV}[SELECT]
The URV may be trimmed to increase the accuracy of the transmitter when using large
turndowns. Apply a pressure equal to the LRV pressure. NOTE:- the accuracy of the reference
pressure should be 3 - 5 times better than the instrument.
{HIT SAVE} will be displayed, there are two choices :-
[SELECT] or[CHANGE] To abort and return to the {TRIM URV} menu.
[[SELECT]] Press and hold to store the ADC offset value, {SAVED} will be
displayed to show that the command is successful.
Commands and HART Numbers used by 2HT
Number Class Local Description
135 D 1 Restore Factory Defaults
148 D V View Trim settings
149 D 2 Set PV Trim Span
151 D 2 Set Password Access for D-CAL
152 D V View Model Number
COMMANDS U Universal C Common D Device Specific
LOCAL ACCESS M Monitor V View
(D-CAL) 1 Access Level 1 2 Access Level 2
HART Commands
These commands are not supported by the transmitter, but will be decoded when the
SHOWHART command is enabled.
Number Class Description
33 C Read Transmitter Variables
39 C EEprom Control
50 C Read Dynamic Variable Assignments
51 C Write Dynamic Variables Assignments
52 C Set Transmitter Variable Zero
54 C Read Transmitter Variable Information
55 C Write Transmitter Variable Damping Value
56 C Write Transmitter Variable Sensor Serial Number
57 C Read Unit Tag, Descriptor, Date
58 C Write Unit Tag, Descriptor, Date
59 C Write Number of response preambles
108 C Write Burst Mode Command Number
109 C Burst Mode Control
110 C Read All Dynamic Variables
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{TRIM LRV}[SELECT]
Apply a pressure equal to the LRV pressure (usually, but not necessarily zero!!) to the
instrument, and allowed to settle. NOTE:- the accuracy of the reference pressure should be 3 -
5 times better than the instrument.