Hardware TankGate Interface
12 Installation and Operations Manual
2.2.3.2 COM1 (RS-232/RS-485) (J5)
Note! On some versions of the TankGate, COM1 is not available
RS-232 is one of the two types of high-speed serial communications channels available
to interface to Host systems using several different protocols. RS-232 will operate at
distances up to 100 feet, while RS-485 allows multidrop communications at distances
up to 4000 feet. RS-232 can be used for flexibility in configuring other types of
communications links. Other variations of RS-232 communications interfaces include
radio, modem and fiber optic interfaces.
The choice of RS-232 or RS-485 is determined by the COM RS-232/RS-485 Selection
Switch SW2
2.2.3.3 COM1 RS232/RS-485 Selection Switch (SW2)
Switch SW2 determines whether RS-232 or RS485 is used. Note that the Hardware
Handshaking Switch SW1 affects the operation of COM1
Figure 2-12:Com1 SW2 Switch 2.2.3.4 COM1 Hardware Handshaking Switch (SW1)
For RS-232, there are two different settings. One setting is used if hardware
handshaking (RTS/CTS) is required. The other setting eliminates the need for hardware
handshaking. Set the Hardware Handshaking Switch to the ‘A’ position to use RTS/CTS
when a modem or signal converter is involved and requires RTS/CTS to operate. The RTS
and CTS signals will be available on terminal block J6. If the connection is direct using
RS-232, jumper RTS to CTS by setting SW1 to the ‘B’ position
Figure 2-13:Com1 SW1 Switch EARTH
NEUTRAL
LINE
SURGE GND
A/TXD
B/RXD
GND
RTS
CTS
TXD
RXD
GND
+15V
+5V
GND
-15V
+
-
VFIELD COM1 COM 0 AUX POWER
VFIELD=48V
VFIELD=24V
RESET
RS232
RS485
COM1
HARDWARE HANDSHAKING
AB
RS232
RS485
COM1
SW2
EARTH
NEUTRAL
LINE
SURGE GND
A/TXD
B/RXD
GND
RTS
CTS
TXD
RXD
GND
+15V
+5V
GND
-15V
+
-
VFIELD COM1 COM 0 AUX POWER
VFIELD=48V
VFIELD=24V
RESET
RS232
RS485
COM1
HARDWARE HANDSHAKING
AB
HARDWARE HANDSHAKING
AB
SW1