Comtech EF Data RSU-503 - Manual (Page 38)

Installation RSU-503 Redundancy Switch Unit
22 Rev. 8
The MTI connector is a 26-pin circular female connector with the following pinouts:
Pin # Name Function
RS-232 RS-485
A GND -RX/TX
B -RX/TX
C +RX/TX
D CTS +RX/TX Clear to Send
E RD/RX Receive Data
F RTS Ready to Send
G TD/TX Transmit Data
H DSR Data Set Ready
J GND Ground
K Reserved
L EXT_PWR Output, 11V for KP-10
M
N EXT FLT1 #A TWT FLT input for primary channel
P EXT FLT1 #B TWT FLT input for secondary channel
R N/C
S Ground Chassis Ground
T Reserved
U Reserved
V Reserved
W Reserved
X FLT NC Summary fault relay, connects to COM with fault
Y FLT COM Summary fault relay, COMMON
Z FLT NO Summary fault relay, opens with fault
a Reserved
b Reserved
c Reserved
Note: Clear to Send (CTS) is tied to Ready to Send (RTS) in RS-232 mode.
2.4.13 GND (ERDE)
GND is a #10-32 stud for the purpose of connecting all units to a common chassis
ground.