15
16
Operating elements
Jumpers J1 and J2 – baud rate
The baud rate is set by means of jumpers J1 and J2.
Therefore, 4 different baud rates can be preset:
J1
J2
Baud rate
ON ON 9600
OFF ON 19200
ON OFF 38400
OFF OFF 57600
Jumper J3 – terminating resistor (at RS 485 only)
The 120 Ω terminating resistor is activated by setting jumper J3.
Button S3 – learning mode, input filter
Mit der Taste S3 wird zwischen der Normal- und der
Pressing button S3 switches between normal operating and learning mode.
Learning mode
Pressing button S3 for 2 seconds switches the gateway to learning mode. LED L3 indicates that status by steady light.
Pressing button S3 for 2 seconds again switches the gateway back to normal operating mode, LED L3 goes off.
Deleting input filter
Starting from normal operating mode, pressing button S3 for more than 6 seconds deletes all stored radio transmitter IDs from the input
filter. LED L3 is flashing. When button S3 is released after that, the gateway switches to learning mode and LED L3 goes on steady light.
Pressing button S3 for 2 seconds again switches the gateway back to normal operating mode, LED L3 goes off.
When the input filter is cleared, operating mode “direct” is active. All radio telegrams received are forwarded to the RS485 bus. As soon
as a transmitter has been learned by the gateway’s input filter, operating mode “direct” is active. Then only radio telegrams received from
such radio transmitters are forwarded to the RS485 bus, of which the transmitter IDs are registered in the input filter.
Note: The filter function can also be switched on and off by a SW command without having to delete already stored IDs.
Button S4 – reset
Pressing button S4 resets all malfunction messages indicated by LEDs.
RS 485
Principle
GW1 - RS 485- FEM radio frequency gateways are connected via screw terminals to the RS 485 bus cable. The bus cable must be twisted-
pair, preferably shielded T-wire cable 1 x 4 x 0.8 mm
2
.
At one RS 485 bus cable, up to 30 devices can be connected, i.e. radio frequency gateways as slaves and PC or PLC systems as master.
The bus cable can be up to 1000 m long, stub lines however should never exceed a maximum length of 15 m.
All bus ends of a RS 485 network cable (also those at stub lines) must be terminated by a 120 Ω terminating resistor. This is accomplished
by setting jumper J3 at the both outermost gateways. If a RS 485 bus cable is not terminated by a resistor, communication problems will
result.
The gateway can be supplied by DC power of 10 - 30 V DC via terminals 1 and 2.
RS485
RS485
RS485
+V A B GND
RS485
station
station
station
station
device No. 1
device No. 2
device No. ..
device No. 32
SPS and
DC-Supply
station
station
station
station
Connecting terminals
Screw terminal block X1 for T-wire cables and strands of 0.5 - 1 mm
2
PIN .................... Name ................ Legend
1 ........................ GND ................... Minus, ground, reference potential
2 ........................ +VDC ................. Plus, voltage supply 10 - 30 V DC
3 ........................ B ........................ Rx – RS 485 data line receiving
4 ........................ A ........................ Tx – RS 485 data line transmitting
5 ........................ GND ................... Minus, ground, reference potential
S3
S4
J1 J2 J3
L5 L4 L3 L2 L1
GND
+VDC
A Tx
B Rx
GND
5
4
3
2
1
