METIS M308 / M309 / M313 / M316 / M318 / M323 / H309 / H316 / H318 (12-pin)
SensorTools Software
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7.2.3.4 Data Collection (Buffer Mode)
The measurement data transfer from pyrometer to the PC can vary depending
on the requirements and computing power. Speed and transferable amount of data are dependent on
the baud rate and the data mode. In the data collection window the amount of measured values are
shown, determined by calculation for each baud rate and each mode. When set to "Auto. interval ad-
justment", the corresponding values of baud rate selection will be entered automatically in the field on
bottom right. When required, they still can be adjusted manually, for example, if the calculated values
still give problems.
Data format:
When measure-
ment data are transmitted, the
amount of transmitted infor-
mation can be selected. The
selection affects the speed.
- Single measured value
(fastest)
:
Saves and transmits the
temperature value shown on
the display. Is used with M3
and H3 models together with
the buffer mode at 921.6 kBd
to ensure error-free high-
speed communication.
- 2-channel compatibility
mode:
Only used when the
measured data should be
transmitted as with ratio py-
rometers, e.g. if a PLC pro-
gramming must have compa-
rable communication with
both devices types.
- With state information:
2-
channel compatibility mode
plus control information (I/O
states, laser targeting active,...). Required for devices with
PID controller
to indicate the setpoint-
value correctly, in addition to the measuring temperature graph.
- With state information and analog input value
(slowest)
:
2-channel compatibility mode plus sta-
tus information including analog input information.
Data mode:
- ASCII mode:
The pyrometer always transfers separate readings to the software and shows each
in the graph as a pixel. In addition to the transmission of measured values, also regularly status
values are transmitted (limit contacts or active laser targeting light...), so that measured values do
not always arrive at the same time interval.
For most applications this speed is sufficient, a modern PC can transmit every 5 ms a value at 921
Kbits.
- Buffer mode:
Measurement data are temporarily stored in the internal pyrometer-buffer and peri-
odically transferred in blocks to the software. The buffer interval defines how fast the internal FIFO
buffer of the pyrometer is filled. The shorter the time, the more data per communication block will
be transferred.
An interval time set too fast in relation to the baud rate and computing power leads to buffer over-
flows, which are represented by vertical bars in the graph. A modern PC reaches intervals of about
0.3 ms at 921.6 Kbits without buffer overflow, at 57 Kbits intervals of approximately 3.6 ms. If buff-
er overflows occur, the interval time can be increased, the baud rate can be increased or unneces-
sary programs and background services be stopped. A minor impact also has the reduction of the
maximum data records in memory (see under
Data Recording
Active mode
Hide adjustment and
additional information
window
Selecting the trans-
mission rate of the
serial interface in
Baud
Automatically take
over measured
values / s
Manually adjust
buffer interval
Information line
Select data / trans-
mission format