Serial Interface Rs232 / Rs485 (M3: Switchable Rs232 / Rs485; H3: Only Rs485) - KPM PROCESS SENSORS METIS M311 Operating Manual

METIS M311 / M322 / H311 / H322 (12-pin device connector)
For activation, input 3 must be activated via the SensorTools software in the device configuration (see
7.1.5)

4.1.5 Serial Interface RS232 / RS485 (M3: switchable RS232 / RS485; H3: only RS485)

The serial interface is used for digital communication of the pyrometer with another computer, for example a
PC for data transmission to the SensorTools software. Via this interface all temperatures are transferred (2-
color and one channel temperatures) as well as device information and parameters.
The maximum transmission speed (Baud rate) is limited by the cable length; it is halved with each doubling of
the transmission path.
▪ RS232: about 7 m cable length with 19.2 kBd. Adjustable are values from 4.8 to 115.2 kBd.
▪ RS485: about 2 km with 19.2 kBd. Adjustable are values from 4.8 to 921.6 kBd.
Connecting one pyrometer via
RS232 or RS485:
In a short RS232 or RS485 connection to the master
(computer receiving the data), the pyrometer is connected
directly as a point-to-point connection with the master.
It is advantageous to connect all interface cables in order
to avoid reflections.
Connecting several pyrometers via RS485:
For a reflection-free operation with longer cables, pay attention to the correct cable termination. Termination at
the physical bus is on front and rear.
Master at
the beginning:
Master in
the middle:
When operating multiple devices (up to 32 are possible), each device needs to assign its own address (directly
on the device or via software SensorTools), under which it can be addressed later. For this purpose, initially,
each device must be connected individually and provided with an address (00-97). After that, all devices can
be connected. If specific parameters for all devices should be changed simultaneously, the global address 98
is used (there is no response from the device). If the address of a device is unknown, you can address each
device independently of the set address with the global address 99 (connect only one device).
A (-) A
B (+) B
DGND GND
Master
Terminating re-
sistor 120 Ω
in the master
or manually
A A
B B
GND
Terminating re-
sistor 120 Ω
Pyrometer 1
Pin 2
Pin 3
Pin 5
RS232 (PC)
RS485
(Master /
PC)
A A A
B B B
GND GND GND
A (-)
B (+)
DGND
Master
TxD Violet
RxD
TxD Red-blue
TxD
RxD Black
GND
RxD Grey-pink
DGND Red
A (-) Violet
A (-)
A (-) Red-blue
B (+)
B (+) Black
GND
B (+) Grey-pink
DGND Red
A A
B B
GND
Terminating re-
sistor 120 Ω
A A
B B
GND
Terminating re-
sistor 120 Ω
... Pyrometer n
Pyrometer
Pyrometer
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