28
Correspondence of instrument: 00H (indicating that the instrument has opened air pump,
zeroing valve and is carrying on 30-second zeroing)
External computer sends 09H orders again and again during the period until the
instrument corresponds ACK (06H).
8.2.5 External computer sends again: 09H (zeroing once again)
Correspondence of instrument: 00H, sending back 06H (ACK) after 30 seconds
8.2.6 External computer transmission
:
02H
(
indicating switching off air pump, exit
)
Instrument response
:
ACK
(
06H
)
Remarks
:
When during the process of external computer control test, the instrument only
is responsible for zeroing, timing for 30 seconds and judging whether it is qualified or not,
testing the HC remained for 30 seconds and judging whether it is qualified or not; making
response to fetch order of the external computer at each 03H and then sending back
immediate data. Other processes controlling and the data processing are responsible by
external computer.
8.3 Under the process of preheat, L.P., zeroing, CLS, ROLL,
ADJ, SET and SCH under the main menu, transmit the above
orders to the host computer, and it responds as BUSY(05H).
When the instrument receives the non-effective order, it will respond as NACK(15H).
8.4 Explanation of data format
8.4.1 ACK(06H) single byte.
8.4.2 HC
:
The HC data is the integer r with symbol (2 bytes). High byte precede while the
unit is ppmvol. For example, the HC concentration is 1234ppmvol, then the HC data is
04D2H (it works as fuel is set as gasoline, and indicated by hexylene. When fuel is set as
LPG, it will be indicated by propane).
8.4.3 CO
:
The CO data is the integer with symbol (2 bytes). High byte precede while the
unit is 100 times of percentage. For example, when the CO concentration is 1.23%, the
CO data is 007BH.
8.4.4 CO
2
:
The CO
2
data represents the same as CO
。