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Hanna Instruments HI 2221 User Manual

Page 31

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31

The instrument will answer for these commands with:

>

where:

is 02 ASCII code character (start of text)
is 03 ASCII code character (end of text)
:
is 06 ASCII code character (recognized command)
is 21 ASCII code character (unrecognized command)
is 24 ASCII code character (corrupted command)

COMMANDS REQUIRING AN ANSWER
The instrument will answer for these commands with:

where the checksum is the bytes sum of the answer string sent as 2 ASCII
characters.
All the answer messages are with ASCII characters.
RAS

Causes the instrument to send a complete set of readings in
according with the current range:

• pH, temperature and mV reading on pH range.
• mV and temperature reading on mV range

The answer string contains:

• Meter mode (2 chars):

• 00 - pH value (0.001 resolution)
• 01 - pH range (0.01 resolution)
• 03 - mV range

• Meter status (2 chars of status byte): represents a 8

bit hexadecimal encoding.
• 0x10 - temperature probe is connected
• 0x01 - new GLP data available
• 0x02 - new SETUP parameter

• Reading status (2 chars): R - in range, O - over

range, U - under range. First character corresponds
to the pH range reading. (Not for HANNA ORP
electrodes with pin.) Second character corresponds
to mV reading.

• pH reading on pH range only - 7 ASCII chars,

including sign and decimal point. (Not for HANNA
ORP electrodes with pin.)

• mV reading - 7 ASCII chars, including sign and

decimal point.

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