Startup - St 700 Standard Transmitter; Overview; Startup Tasks; Output Check Procedures - Honeywell ST 700 User Manual

Startup – ST 700 Standard Transmitter
4.7

4.7.1 Overview

This section identifies typical start up tasks associated with several generic pressure measurement
applications. It also includes the procedure for running an optional analog output check.

4.7.2 Startup Tasks

After completing the installation and configuration tasks for a Transmitter, you are ready to start up the
process loop. Startup usually includes:

Checking zero input

Reading inputs and outputs

Applying process pressure to the transmitter.
You can also run an optional output check to wring out an analog loop and check out individual
Process Variable (PV) outputs in Digitally Enhanced (DE) mode before startup.
The actual steps in a startup procedure vary based on the type of Transmitter and the measurement
application. In general, the procedures in this section are based on using Honeywell MC Toolkit to
check the Transmitter input and output under static process conditions, and make adjustments as
required initiating full operation with the running process. Note that similar checks can be made using
the optional three-button assembly, where the Transmitter is equipped. Operation with the three-
button assembly is discussed in the Operation section.
When the Standard Display is connected, the two-button assembly for the Standard Display is
present. The buttons will function 1 second after powering up.

4.7.3 Output Check Procedures

The Output Check comprises the following procedures:

The Loop Test procedure checks for continuity and the condition of components in the output
current loop.

The Trim DAC Current procedure calibrates the output of the Digital-to-Analog converter for
minimum (0%) and maximum (100%) values of 4mA and 20mA, respectively. This
procedure is used for Transmitters operating online in analog mode to ensure proper
operation with associated circuit components (for example, wiring, power supply, control
equipment). Precision test equipment (an ammeter or a voltmeter in parallel with precision
resistor) is required for the Trim DAC Current procedure.

The Apply Values procedure uses actual Process Variable (PV) input levels for calibrating
the range of a Transmitter. To measure a liquid level for example, a sight-glass can be used to
determine the minimum (0%) and maximum (100%) level in a vessel. The PV is carefully
adjusted to stable minimum and maximum levels, and the LRV and URV are then set by
commands from the MC Toolkit.
The Transmitter does not measure the given PV input or update the PV output while
it operates in the Output mode.
Page 24
ST 700 SmartLine Pressure Transmitters User's Manual
Revision 8.0