Dwyer GFT2 User Manual

Page 17

Number

Indication

LCD Display remains blank when unit is
powered up. Status LED is OFF.

LCD Displays flow reading, but 4 to 20
mA Set Point output signal does not
change.

Fluid flows throught he flow
meter/controller, but the LCD Display
and/or Totalizer reading does not
respond to the flow.

Fluid flows through the flow
meter/controller and LCD Display Flow
Rate reading responds to flow, but
Totalizer reading is not changing.

Erratic Flow Rate reading.

Totalizer reading is wrong.

LCD Displays flow reading, but
communication interface does not work.

The Device Diagnostic Alarm Event with
code 0 - "CPU Temp. High" is active.

The Device System Event with code D -
"Fatal Error" is active.

Likely Reason

Power Supply is bad, or polarity is reversed.

PC board is defective.
Wrong configuration of J2 Input/Output
Jumpers.
External loop is open, or load resistance is
more than 600 Ohm.

External loop is open, or load resistance is
more than 600 Ohm.

The fluid flow rate is below set Low Flow Cut-
Off value.
Wrong configuration of J2 Input/Output
Jumpers.

PC board is defective.

The fluid flow rate is below set "Totalizer #1
Flow Start" parameter value.

Totalizer mode is disabled.

Totalizer Power On Delay parameter is set to
high value and Totalizer is disabled by
firmware.
Wrong configuration of J2 Input/Output
Jumpers.
GFT2 "Full-Scale Flow" parameter value (in
L/min) is not equal to the mated device full-
scale range.
GFT2 "Fluid Std. Density" parameter is not set
according to fluid being used and mass based
engineering units are selected.
Wrong configuration of J2 Input/Output
Jumpers.
GFT2 "Full -cale Flow" parameter value (in
L/min) is not equal to the mated device full-
scale range.
Wrong host PC interface or wiring connection.

GFT2 has RS-485 interface but device
address does not match addressed used by
host PC.

MCU/PCB temperature is too high (overload).

Fatal Error (EEPROM or SRAM corrupted).

Solution

Measure voltage on pins 2 and 1 of the DB9 interface terminal
connnector. If voltage is out of specified range, then replace
power supply with a new one. If polarity is reversed (reading is
negative), make correct connection.
Return device to factory for repair.
Check J2 jumper configuration (see Table 9).

Check for external connections to pins 5 and 6 of the DB9
interface terminal connector. Make sure the loop resistance is
less than 400 Ohm for 12 VDC power supply option and 900
Ohm for 24 VDC power supply option.
Using Key Pad, navigate to submenu "Device Diagnostic" and
select submenu "Analog Output Value". Record the DAC counts
values and consult the factory with findings.
Check settings for Low Flow Cut-Off value and make required
adjustment (see Submenu "Low Flow Cut-Off").
Check J2 input jumper configuration (see Table 9). If necessary,
contact factory for additional help.
Using ESD precautions, measure voltage on pins 4 and 6 of the
DB9 interface terminal connector. If voltage correlates with flow
meter/controller output signal, check ADC counts. Using Key Pad,
navigate to Submenu "Device Diagnostic" and selet Submenu
"ADC Input Counts". Record the ADC counts values and consult
the factory with findings.
Check settings for "Totalizer #1 Flow Start" value and make
required adjustment (see Submenu "Totalizer #1 Flow Start").
Check settings for "Totalizer #1 Mode" parameter. Make sure
Totalizer Mode is set to "Enabled" (see Submenu "Totalizer #1
Mode").
Check settings for "Totalizer Power On Delay" (see Submenu
"Totalizer #1 Power On Delay"). If settings are too high, make
required adjustment.
Check J2 input jumper configuration (see Table 9). If necessary,
contact factory for additional help.
Check settings for "Full Scale Range" (see Submenu "Device
Calibration"). Full Scale Range parameter has to be set equal to
the mated device full scale flow rate in L/min.
Check settings for "Fluid Std. Density" (see Submenu "Device
Calibration"). This parameter is required only when mass-based
engineering units are selected.
Check J2 input jumper configuration (see Table 9). If necessary,
contact factory for additional help.
Check settings for "Full Scale Range" (see Submenu "Device
Calibration"). Full Scale Range parameter has to be set equal to
the mated device full scale flow rate in L/min.
Make sure interface type (RS-232 or RS-485) on the host PC is
the same as on the GFT2 device. Check communication wiring
connection according to "Digital Communication Interface
Connections".
Change GFT2 RS-485 address to match host PC software
settings.

Disconnect power from the GFT2. Make sure the ambient
temperature is within specified range (below 158°F or 70°C). Let
the device cool down for at least 15 minutes. Apply power to the
device and check Diagnostic Alarm Event. If overload connection
will be indicated again, the unit has to be returned to the factory
for repair.
Cycle the power on the GFT2. If System Event with code D
indicates again, the unit must be returned to the factory for repair.