Flowserve 3400IQ Digital Positioner - Manual (Page 30)

Logix 3400IQ Digital Positioner FCD LGENIM3402-00 – 0/07
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input impedance cannot be less than 3k ohms. This will vary according to frequency of the fieldbus
communications. Typical power requirements are 23 mA @ 9-32 VDC.
NOTE: The user cannot measure across the terminals of an un-powered Logix 3400IQ digital
positioner and get the effective resistance. It is an impedance device, not a resistive device.
5.4 Powering Up the Logix 3400IQ Digital
Positioner
Pre-power Checklist
Before applying power to the fieldbus network the user should make the following checks:
Verify that the Logix 3400IQ digital positioner has been properly mounted and connected to a
system.
The Logix 3400IQ digital positioner has been properly wired to a fieldbus network.
The Logix 3400IQ 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 3400IQ 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 3400IQ
digital positioner. See Section 6.5, Setting Write-protect Feature and Section 10.8, 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 3400IQ digital positioner.
3. Verify that the terminal voltage is within the limits listed in Table 4.2, Logix 3400IQ Digital
Positioner Power Requirements.
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