33
USBhost / RS485 converter
3/ constrUction
The USBhost/RS485 converter according to Fig. 1 with the panel Fig. 2 is installed in
a plastic box designed for spaces with the maximum voltage of 50 V
AC
. There is a 1 m long
USB cable with USB B (M) connector running out from the left side. There are 4 screw-
on terminals on the right side, 2 for the RS485 serial interface and 2 for the power supply
(see Tab. 1). The max. cross-section of connected conductors is 1.5 mm
2
.
Tab. 1: Table of USBhost/RS485 converter terminals
Terminals
Description
A (RxTx+)
bidirectional data
B (RxTx−)
bidirectional data
+12 V
supply voltage from + 6 to + 16 V
⊥
signal ground
4/ installation
Before installation, FW must be installed in MEg40
+
allowing the addressing. By default,
MEg40
+
with the USB interface includes FW, for which no addressing is assumed.
The
schematic
diagram
of
converter
in
communication
chain
MEg40
+
→
USBhost / RS485
→
MEg202.2 is shown in Fig.3. USB cable with connector
B (M) is shown in Fig. 2. The USB cable with the connector B (M) is intended to
be connected into the universal instrument MEg40
+
. Through this connector, the USB
interface of the instrument MEg40
+
is also supplied as specified by the USB interface
standard. Through screw-on terminals, the converter is connected to terminals of the
communication unit MEg202.2; for interconnection of the terminals see Table 2.
Tab. 2: Interconnection of USBhost/RS485 converter and communication unit MEg202.2
USBhost / RS485
converter
MEg202.2
Chan1
Chan2
A
3
7
B
4
8
+12 V
1
5
⊥
2
6
Summary of Contents for MEg40+
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Page 43: ...M c Energetick Apar ty 43...
