Instruction Manual

Instruction Manual

D103557X012

Wiring Practices

January 2015

Section 2 Wiring Practices22

Logic Solver or Control System Requirements

There are several parameters that should be checked to ensure the logic solver or control system is compatible with

the DVC6200 SIS digital valve controller.

HART Filter / Line Conditioner

Depending on the logic solver or control system and operational mode of the DVC6200 SIS digital valve controller, a

line conditioner or HART filter may be required.

Operational Mode

Control System

or Logic Solver

HART Filter

Required?

Line Conditioner

Required?

4-20 mA

Point-to-Point Loop

PROVOX™, RS3™,

DeltaV™, Ovation™

No No

All Others Consult Sales Office No

24 VDC

Multi-Drop Loop

All No Yes

The HF340 HART filter and LC340 Line Conditioner are passive devices that are inserted in the field wiring of the HART

loop. A filter or line conditioner is normally installed near the field wiring terminals of the system I/O (see figure 2‐1).

Its purpose is to effectively isolate the system output from modulated HART communication signals and raise the

impedance of the system to allow HART communication. For more information, refer to the HF340 HART filter

(D102796X012) or LC340 Line Conditioner (D102797X012) instruction manual.

Voltage Available

The voltage available at the DVC6200 SIS digital valve controller must be at least 10 VDC. The voltage available at the

instrument is not the actual voltage measured at the instrument when the instrument is connected. The voltage

measured at the instrument is limited by the instrument and is typically less than the voltage available.

As shown in figure 2‐1, the voltage available at the instrument depends upon:

D The logic solver or control system compliance voltage

D if a line conditioner filter or intrinsic safety barrier is used, and

D the wire type and length.

The compliance voltage is the maximum voltage at the logic solver or control system output terminals at which the

system can produce maximum loop current.

The voltage available at the instrument may be calculated from the following equation:

Voltage Available = [Compliance Voltage (at maximum current)] - [line conditioner/filter voltage drop] - [total cable

resistance  maximum current] - [barrier resistance x maximum current].

The calculated voltage available should be greater than or equal to 10 volts DC.