Fluke endurance series, Руководство пользователя

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Endurance® Series
Users Manual
32
5.5.5. Computer Interfacing via RS485 link
The distance between the sensor and a computer can be up to 1200 m (4000 ft.) via RS485
interface. This allows ample distance from the harsh environment where the sensing system is
mounted to a control room or pulpit where the computer is located. The USB/RS485 Interface
Converter allows you to connect your Endurance
®
sensor to computers by using an USB
interface.
With auto configuration, the converter is able to automatically configure RS485 signals without
external switch setting. The converter is equipped with 3000 VDC of isolation and internal
surge-protection to protect the host computer and the converter against high voltage spikes, as
well as ground potential difference. When the converter is connected the computer gets one
virtual COM port.
Technical Data
Power supply 5 VDC direct from USB port
Speed max. 256 kBit/s
RS485 4 wire (full duplex) and 2 wire (half duplex)
Terminal screwed accepts 0.05 to 3 mm² (AWG 13 to AWG 30)
USB connector type B (supplied with type A to type B cable)
Ambient Temperature 0 to 60°C (32 to 140°F), 10-90% relative humidity,
non-condensing
Storage Temperature -20 to 70°C (-4 to 158°F), 10-90% relative humidity,
non-condensing
Dimensions (L x W x H) 151 x 75 x 26 mm (5.9 x 2.9 x 1 in)
Only the 2-wire (half duplex) RS485 communication is supported on Endurance
®
devices with
the M16
– 12 pin standard connector. The disadvantage is that the data transfer is just
alternating possible in one direction at a time. The maximum communication baud rate between
the Endurance
®
device and the USB/RS485 converter is 115.200 kBaud. A Baud rate of 38.4
kBaud is the default (preset) value in the Endurance
®
series device during factory setup.
Just the 2-wire (half duplex) mode is supported in serial RS485
communication by Endurance
®
devices with M16
– 12 pin connector!
The 4-wire full duplex serial RS485 communication is only possible, if the
cable gland/grommet variant is choosen and a customer specific cable is
correctly wired to the inside pin header in the electronics housing.
Figure 21: USB/RS485 Converter (E-USB485)
Multiple Endurance
®
sensors in a RS485 Multidrop Network Wiring
For an installation of two or more Endurance
®
sensors in a RS485 network (2-wire, half duplex),
each Endurance
®
sensor needs it’s specific RS485 network address (1 - 32), preset via the
Endurance
®
control panel (user interface) or alternatively via a standard terminal program
(operating system dependent). Once all the units are addressed, wire up the units in the 2-wire