© 2020 Van Putten Instruments BV | MAN-VP-V-UK | Revision: 2000 | Date: 29-7-2020
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9.3
Troubleshooting
9.3.1
Problems and solutions
This section will address common problems and their resolution.
Issue
Sympton
Cause
Resolution
Cannot find VPVision in my
netw ork
IP conflict, IP address out of
range
Re-connect to LAN 1 w ith a
direct Ethernet connection.
VPVision page is not
updating
All w idgets are static
Connection problems w ith
remote IO, netw ork off line,
sw itch off line
Restart DAQ process via the
configuration backend.
Communication problem
No data on screen
Modbus address not
properly assigned, Modbus
conflict
No LED blinking
Wrong Com port assignment Check Com port in Device
Configuration
TX LED blinking, but no
RX LED.
Wrong w iring
Sw ap RX and TX (A and B)
w ire and see if this
resolves. Disconnect all but
one Modbus device to isolate
the problem.
Wrong w iring
Check device settings like
baud rate, parity, stop bits
TCP/IP converter TX and RX
not blinking
IP conflict, or not properly
configured converter
Refer to converter user
manual. Configure IP
address. Use Modpoll to
debug the connection.
Wrong kW measurement
Wrong kW in display
The VPlog i is just an
Ampere meter... make sure
that the voltage and pow er
factor is as correct as
possible
If not good enough--> invest
in a real kW meter w ith
Modbus (Shark, Wattnode).
Analog input configuration
VPVision show s 0 as
measurement value
The Moxa module has been
reset or the configuration is
lost
Log in to the Moxa internal
w eb server, enable user
defined Modbus addresses
and set all read out
parameters to be located in
the holding registers
9.3.2
Communication issues
RS485 Modbus related issues
Check LED indicators on the RS485 converter. Both TX (Transmit) and RX (Receive) should blink
intermittent. Blinking led, once per second: VPVision Data Acquisition is active.
Check termination and biasing resistors. They should be enabled in the last Modbus Junction Box
only.
Ethernet issues
Ethernet issues can be localized by pinging the individual components of the system. Each Ethernet
device has a unique IP address. The addresses can be pinged and when they respond, you know
that the device is reachable. An unreachable device will result in a request time out.
