Flowserve 400MD Logix - Manual (Page 23)

Answer: FF specifies a 10-32V operation range. A fieldbus compatible power supply with terminators should be used. NOTE: The Logix 3400MD is driven
from a voltage source, not the typical 4-20 mA supply.
Question: I accidentally reversed the voltage supply across the Logix 3400MD digital positioner. How do I know if I damaged something?
Answer: The Logix 3400MD is non-polarized. Inadvertent connection of the fieldbus supply shouldn’t damage the unit.
Question: What is the input resistance of the Logix 3400MD digital positioner?
Answer: The Logix 3400MD digital positioner does not have a simple resistive input. This is because the Logix 3400MD digital positioner is an active device.
The fieldbus specifications dictate that the
input impedance cannot be less than 3k ohms. This will vary according to frequency of the fieldbus communica-
tions. Typical power requirements are 23 mA @ 10-32 VDC.
NOTE: The user cannot measure across the terminals of an un-powered Logix 3400MD digital positioner and get the effective resistance. It is
an impedance device, not a resistive device.
5.4 Powering Up the Logix 3400MD Digital Positioner
Pre-power Checklist
• Before applying power to the fieldbus network the user should make the following checks:
• Verify that the Logix 3400MD digital positioner has been properly mounted and connected to a system.
• The Logix 3400MD digital positioner has been properly wired to a fieldbus network.
• The Logix 3400MD digital positioner housing has been properly connected to a suitable earth ground.
• The operator station or host computer has been installed and connected to the fieldbus network.
NOTE: If the user wants to enable the write-protect feature or change the operating mode of the Logix 3400MD digital positioner to simulation mode, the
user must change hardware dip switches on the internal electronics boards. This may require that the power be removed from the Logix 3400MD digital
positioner. See Section 6.5, Setting Write-protect Feature and Section 10.9, Simulation Mode for details.
Power Up Procedure
To apply power to the fieldbus network, perform the following steps:
1. Turn on all power supplies that furnish DC power to the fieldbus network.
2. Use a digital voltmeter and measure the DC voltage across the + and - Signal terminals to the Logix 3400MD digital positioner.
3. Verify that the terminal voltage is within the limits listed in Table 4.2, Logix 3400MD Digital Positioner Power Requirements.
6 Logix 3400MD Digital Positioner Configuration
6.1 Introduction
This section explains the tasks to establish communications and configure the Logix 3400MD digital positioner for the process application. An overview is
given of the configuration tasks using the NI-FBUS Configurator application as an example. Detailed information on using the configurator application is
found in the user manual supplied with the software.
Prior to installing the Logix 3400MD refer to sections 5, 6 and 7 in the Logix 3400MD IOM for informa tion on how to mount, install, wire and start up a
Logix 3400MD.
Logix 3400MD Digital Positioner LGENIM3405-02 11/13
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