15
TABLE 2 — DATA PORT CONNECTOR ELECTRICAL CONNECTIONS
Pin Number
Channel 1
RS232
Channel 2
RS232
Channel 2
RS422
2- or 4-Wire
Channel 2
RS485
2-Wire
1
Channel 2
RS485
4-Wire
Channel 2
Manchester
Bi-Phase
2
1
Chassis/ Signal
Common
Chassis/ Signal
Common
Chassis/ Signal
Common
Chassis/ Signal
Common
Chassis/ Signal
Common
Chassis/ Signal
Common
2
Input (Rx)
N/A
N/A
N/A
N/A
N/A
3
N/A
Output (Tx)
OUT +
I/O +
OUT +
OUT +
4
N/A
Input (Rx)
IN +
I/O +
IN +
IN +
5
N/A
N/A
IN –
I/O –
IN –
IN –
6
N/A
N/A
OUT –
I/O –
OUT –
OUT –
7
Output (Tx)
N/A
N/A
N/A
N/A
N/A
8
Chassis/ Signal
Common
Chassis/ Signal
Common
Chassis/ Signal
Common
Chassis/ Signal
Common
Chassis/ Signal
Common
Chassis/ Signal
Common
1
Pins 3 and 4 and pins 5 and 6 are shorted internally in this mode and either or both may be used for the signal connections.
2
Manchester/Bi-Phase is normally a simplex connection, although this duplex unit will transport signals in either/both directions.
C
ONNECTING THE
D
ATA
P
ORTS
Data ports can be wired as shown in the following examples. Many different manufacturers of equipment
mark their terminals differently. The data ports on one end of the link may be set to a different data type
than the opposite end. For example, the Receiver end may be set for RS232 to communicate with a PC type
computer port and the opposite end of that data link may be set to RS422 or RS485. No external data
conversion units would be required.
RS232
RS232 is a “point-to-point” or “one-to-one” connection allowing only one transmitter and one receiver per
electrical link. Care should be taken to insure that the Tx or transmitting end on one end of the electrical link
is connected to a receiver or Rx signal on the other. Depending on whether the devices are Data
Communications Equipment (DCE) or Data Terminal Equipment (DTE), the Tx and Rx marking will change.
The 9482D RS232 terminals are called Tx (an output) and Rx (an input).
RS422
AND
RS485
RS422 simplex is a “one-to-many” or “daisy chain” connection allowing up to 10 receivers to be electrically
connected to one transmitter. Markings on RS422 devices vary, with Tx+, Rx+, Tx–, and Rx– being common,
as well as TA, TB, RA, and RB. Normally the TA and RA signals are the – signals, with T being an output and
R being an input. The TB and RB signals are the + signals. The termination resistors on the last receiving
device in the electrical daisy chain of receivers should have its termination resistors turned on. Refer to the
example drawings at the end of this section for examples.
RS422 duplex is a one-to-one connection. In RS422 duplex, you are limited to one transmitter at each end of
the link. This is because to connect more than two transmitting devices on one electrical link in RS422 is not
allowed. Markings on RS422 devices vary with TX+, RX+, TX–, and RX– being common, as well as TA, TB, RA,
and RB. Normally the TA and RA signals are the – signals, with T being an output and R being an input. The
termination devices on both ends of the link should be enabled.
Summary of Contents for 9482-DR
Page 2: ......
Page 19: ...19 FIGURE 10 RS422 AND RS485 TERMINATION EXAMPLES...
Page 20: ...20 FIGURE 11 RS422 TERMINATION EXAMPLES FIGURE 12 RS422 TERMINATION EXAMPLES...
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