User manual

AGM Spread Spectrum Radio Manual
8
Hardware Installation
Connecting to RS485 devices
Connecting a SSR to any device using RS485 is the same regardless of the device
connected. To connect one or more RS485 devices you will need a shielded twisted pair
cable.
1. Connect one wire of the twisted pair cable to pin 9 or 10 of the green connector. The
other end of the wire should be connected to +RS485 on the RS485 device.
2. Connect the other wire of the twisted pair cable to pin 7 or 8 of the green connector.
The other end of the wire should be connected to -RS485 on the RS485 device.
3. If using shielded cable you may connect the shield to either pin 5 or 6 of the green
connector. To prevent ground loops the shield of the cable should only be connected
at one location when the SSR and RS485 device share the same power supply. If
separate power supplies are used you may connect the shield to both locations,
however watch for any ground loops that may be created.
4. If additional RS485 devices are to be used, connect the next device. Two terminals
are provided on the SSR for daisy chaining the RS485 cable. Connect the next
RS485 device with +RS485 to pin 9 or 10 and connect the –RS485 to pin 7 or 8 using
the pin not connected to the other RS485 device.
5. When all devices are connected the RS485 buss may require termination resistors. If
the SSR is the last device on the buss, install 120 – 150 ohm resistors across the pins
8 and 10 or pins 7 and 9 depending on which pair is open. Install these terminating
resistors on the first and last device only. If the RS485 cable run is less than 100 feet,
installed in the same enclosure, and you do not encounter any communications
problems the terminating resistors may be omitted.
6. The SSR must be configured for use with RS485. If the “4” light is on then the SSR is
configured for RS485, otherwise the SSR must be configured. You may configure the
SSR for RS485 without removing the RS485 connections by plugging your computer
into the RS232 connection. See the Connecting to Personal Computer and
configuration sections for configuring the SSR.
Connecting to AGM Data Handler (DH) RS232
To connect a SSR to a RS232 Data Handler you will need a 9 pin female to 9 pin male null-
modem cable.
1. Plug one end of the RS232 cable into the 9 pin male connector on the Data Handler.
2. Plug the other end of the RS232 cable into the 9 pin female D connector on top of the
SSR.
3. Power up both the Data Handler and SSR. If properly connected the “2” light will be
on. If not on then check your cable connections.