Teledyne 9110EH - Nitrogen Oxides Analyzer - Manual (Page 94)

Operating Instructions Model 9110EH Instruction Manual
CAUTION
Cables that appear to be compatible because of matching connectors may incorpo-
rate internal wiring that make the link inoperable. Check cables acquired from
sources other than T-API for pin assignments before using.
6.9.3. COM Port Cable Connections
There are two DB-9 connectors on the M9110EH rear panel. COM1 is a male connector, COM2
a female connector (Table 0-16 lists pin assignments). T-API offers two mating cables, one
of which should be applicable for your use.
• Part number WR000077, a DB-9 female to DB-9 female cable, 6 feet long. Allows
connection of COM1 with the serial port of most personal computers. Also available
as Option 60 (Section 5.8.1).
• Part number WR0000024, a DB-9 female to DB-25 male cable. Allows connection to
the most common styles of modems (e.g. Hayes-compatible) and code activated
switches.
Both cables are configured with straight-through wiring and should require no additional
adapters.
To assist in properly connecting the serial ports to either a computer or a modem, there are
activity indicators just above each COM port. When power is applied to the analyzer, the red
LED should be illuminated. If this LED is dark, it indicates a communications error between
serial port and CPU.
Once a cable is connected between the analyzer and a computer or modem, both the red
and green LEDs should be on. If not, COM1 can be switched between DTE and DCE modes
using a small switch on the rear panel to exchange the receive and transmit lines
(emulating a cross-over or null-modem cable). If both LEDs are still not illuminated, check
the cable for proper wiring. For COM2 it may be necessary to install a null-modem cable
(contact customer service for information).
6.9.4. COM2 Configuration
As delivered from the factory, COM2 is configured for RS-232 communications. This port
can be re-configured for operation as a non-isolated, half-duplex RS-485 port with a 150 Ω
termination resistor (Table 0-18 shows the pin assignments of the DB-9 connector).
For RS-485 operation, jumper JP3 on the CPU board should be installed and switch 6 of
SW1 should be set to the ON position. For RS-232, remove the jumper and set the switch to
OFF (default). JP3 is just to the right of the third connector from the left on the top of the
CPU board (as seen from the inside of the analyzer). SW1 is in the middle of the CPU board
between disk-on-chip and BIOS. For non-terminated RS-485 operation, remove the jumper
on JP3 but leave switch 6 in the ON position. Refer to Figure 3-7 to locate the CPU board.
80 M9110EH Rev 0