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QTERM-IV/P40 User's Manual
Beijer Electronics Fax 801-466-8792 Web www.beijerelectronicsinc.com Phone 801-466-8770
The QTERM-P40 does not monitor or control any of the
EIA-232 modem-control lines (such as RTS and DTS).
Handshaking between the host and the QTERM-P40 is
done using software XON/XOFF commands. The XON/
XOFF operation can be disabled (via software commands
or the QDATA file) if you do not wish to have it operate.
6.2.2
EIA-422 Interface
With proper cables and grounding, the EIA-422 interface
can communicate up to a distance of 1000 meters. Since the
EIA-422 version of the QTERM-P40 requires four commu-
nication lines and two power lines, the dig0 and dig1 lines
are not available.
The EIA-422 unit does not have the 120
Ω
line termination
resistor often used to terminate an EIA-422 interface. If you
need this resistor, you can install it on the main PC board.
Figure 6-4 shows where the resistor is to be soldered in. Do
not attempt to remove the PC board from the case.
For volume orders, Beijer Electronics can supply the
QTERM-IV with this resistor installed.
6.2.3
5-volt Buffered Interface
When used to communicate with another 5-volt Buffered
device, the QTERM-P40 can operate at distances up to 5
meters. The advantage of the 5-volt Buffered QTERM- P40
is that it is lower power than the EIA-232 version, and uses
the same 5-volt logic levels as come directly out of a UART
(i.e. the idle state is at 5 volts, and the active state is a 0).
Table 6-1: QTERM-P40 Pin Assignments.
DB9
Female
10-Pin
Terminal Strip
QTERM-P40
232/5-volt Buffered
Function
QTERM-P40
422
Function
QTERM-P40
485
Function
3
4
receive
+receive
dig0*
6
5
dig1*
-receive
dig1*
2
6
transmit
+transmit
RTx+
1
7
dig0*
-transmit
RTx-
9
8
+V
+V
+V
5
9
ground
ground
ground
n/a
1
E-stop N.O.
E-stop N.O.
E-stop N.O.
8
2
E-stop com.
E-stop com.
E-stop com.
7
3
E-stop N.C.
E-stop N.C.
E-stop N.C.
Tx and Rx directions are with respect to the QTERM-P40
*these lines are optional; see section 6.3.3
Figure 6-2. QTERM-P40 Connector Pin Numbering.
