4-5
4
4.2.2
2367 Differences
The 2367 provides a Serial Interface instead of the GPIB interface provided
by the 4867. The RS-232 is a full duplex interface with transmit and receive
signals. There are no handshaking lines because of the short string lengths
of the 4867 commands and responses. The RS-232 transceiver chip has an
internal charge-pump that generates bipolar voltages to power the RS-232
driver chip. A jumper selects the RS-232 or RS-422 driver chip as the source
of the SD(b) signal.
The RS-485 (RS-422) interface is a half duplex interface with a two + and
- signal pairs. The transmitter is firmware programmed so that it is
continuously enabled or is only enabled when the 4867 is responding to a
query. The receiver can be jumper set so that its disabled (RS-232 mode),
set continuously on or set on when the driver is disabled.
Pullup and pulldown resistors are provided on the 2367 to bias floating RS-
422 and RS-485 signals into the mark state to avoid receiver errors.
On OEM board versions of the 2367, headers are provided for LED and
optional serial interfaces. Power connections are made to a two-screw
terminal block adjacent to the power supply.
4.2.3
4807 Board Differences
The 4807 is an small board version of the 4867 with the same firmware and
Analog-Digital I/O Interface as described for the 4867. The 4807 does not
have an on-board power supply so it is powered by regulated 5 Vdc. The
4807 has its GPIB interface on a 26 pin header that also includes the GPIB
address switch inputs.
4.2.4
2307 Board Differences
2307 version boards have a serial interface as shown in Figure 4-2 instead
of the 4867's GPIB interface. The 2307's serial interface has both RS-232
and RS-422/RS-485 capability.
The RS-232 is a full duplex interface with transmit and receive signals.
There are no handshaking lines because of the short string lengths of the
4867 commands and responses. The RS-232 transceiver chip has an internal
