Enter text characters in the Text to be sent box, then click Send. If the serial link is operating
correctly, the exact same text will be displayed back from the instrument in the Echo box. Choose
Cancel to exit from this test box.
Keyboard test
The Troubleshooting, Keyboard Test will reveal whether all the analyzer buttons are functioning
correctly.
Press any one of the instrument's buttons (except the ON/OFF button) for a full second or more. The
appropriate square on-screen should darken. Choose Cancel to exit from this test box.
Display test
Choosing Troubleshooting, Display Test lets you perform a one-way communication between
computer and instrument.
Type a number (with or without a decimal point) in the Number box, select the measurement Units,
and then click Send. The number entered and the indicator bar placement, should appear on your
instrument LCD.
Clock settings
Choose the Clock settings command to set the date and time in the instrument.
The first screen displays the current date and time as set in the instrument. If this is correct, choose
Ok, else if either date or time must be changed, choose Modify to bring up the next screen. Enter
the current date and time and choose Ok to store the entry into the instrument. All measurements will
be noted with the appropriate date and time when they are downloaded to the Hach 3654 program.
Analog voltages view
The Troubleshooting, Analog Voltage View gives a real-time look at voltages used by the system
to transmit information about sensor current, temperature and pressure. This is useful when trying to
identify an instrument problem with a Hach Lange service representative either on-site or over the
phone.
When performing this test, if the system is over-range, you may receive a message that states, for
example, The current input is saturated. Similar messages will also appear, to warn when
temperature and pressure limits are exceeded.
The voltage limits for normal operation are:
• Current channel: +0.1 V and +4 V, depending on the gas being measured
• Temperature channel: +10 mV to +4 V
• Pressure channel: -100 mV to +100 mV
The POINT window on the right side of the gas channel voltage, is a parameter useful for
troubleshooting by Hach Lange support technicians. It cannot be set or updated locally.
Measurements view
The Troubleshooting, Measurements View confirms, on your PC monitor, what your instrument
should be displaying on the LCD for gas concentration and sample temperature. Choose Cancel to
exit from this display.
Troubleshooting - Operation
Program identification
In case of problems, it may be necessary to check the current version of your software as this may
be required by Hach Lange if you need to contact them for assistance in problem solving.
To identify the version of the software in your instrument, switch off the instrument. Then hold down
the MEAS button while switching the instrument back on. The instrument will then briefly display the
software version number before going through it's start-up procedures.
Diagnostics messages
The following are warning messages that may appear on the instrument LCD in place of the gas
concentration.
28 English