6
Signal Connections
The signal connections for the XRD-8050 follow the recommended EIA DCE
format for RS-232. These connections are described below and must be compat-
ible with the equipment being used. All signal connections are made via an
industry standard DB-25S connector.
Power Supply Connections
12 to 18 volts AC
Position 1 of 3 position terminal block
12 to 18 volts DC
Position 2 of 3 position terminal block
AC or DC Return (Common)
Position 3 of 3 position terminal block
Anti-Streaming Time-Out
The XRD-8050 contains an internal timer which will block the RS-232 input
signal to any unit in the event that a faulty data streaming condition is produced
by any traffic signal controller. This timer is triggered by the rising edge of the
RTS signal. When the pre-set time interval is exceeded, the CTS line will be
forced low and the data input to the XRD-8050 blocked, thereby preventing
system lockup. The unit will then remain in the blocked state until the RESET
button on the front panel on the unit is pressed. Only the XRD-8050 connected
Description
EIA Designation
DB-25S Pin Number
Chassis Ground
(AA)
1
Transmitted Data
(BA) (input)
2
Received Data
(BB) (output)
3
Request to Send
(CA) (input)
4
Clear to Send
(CB) (output)
5
Data Set Ready
(CC) (output)
6 (jumped to 20)
Signal Ground
(AB)
7
Data Carrier Detect
(CF) (output)
8
Data Terminal Ready
(CD) (input) 20 (jumped to 6)
All other signal pins are not utilized.
11
XRD-8050 in RECEIVE MODE
Pin Description
Condition
1
Chassis Ground
(input/output)
0 VDC
2
Transmitted Data
(input)
Undetermined
3
Received Data
(output)
Pulses at data rate
4
Request to Send
(input)
+3.75 to +15 VDC
5
Clear to Send *
(output)
+3.75 to +15 VDC
6
Data Set Ready
(output)
Same as Pin 20
7
Signal Ground
(input/output)
0 VDC
8
Data Carrier Detect
(output)
+3.75 to +15 VDC
20
Data Terminal Ready
(input)
Jumpered to Pin 6
* Clear to Send will only remain in this state if the anti-streaming timer has not
been triggered.
In addition to the above, check that the ANTI-STREAMING time-out interval is
correct for the data rate being used and that the MASTER/LOCAL switches are
set properly. Also refer to both the general troubleshooting techniques and
those regarding fiber optic cable.
