Teledyne GFC-7001T - Trace CO Analyzer - Manual (Page 56)

Getting StartedTeledyne API – Model T300/T300M CO Analyzer
Teledyne Analytical Instruments 56
RS-232 M ULTIDROP O PTION C ONNECTION
When the RS-232 Multidrop option is installed, connection adjustments and
configuration through the menu system are required. This section provides instructions
for the internal connection adjustments, then for external connections, and ends with
instructions for menu-driven configuration.
Note Because the RS-232 Multidrop option uses both the RS232 and COM2
DB9 connectors on the analyzer’s rear panel to connect the chain of
instruments, COM2 port is no longer available for separate RS-232 or
RS-485 operation.
ATTENTION COULD DAMAGE INSTRUMENT AND VOID WARRANTY
Printed Circuit Assemblies (PCAs) are sensitive to electro-static
discharges too small to be felt by the human nervous system. Failure to
use ESD protection when working with electronic assemblies will void
the instrument warranty. Refer to Section 14 for more information on
preventing ESD damage.
In each instrument with the Multidrop option there is a shunt jumpering two pins on the
serial Multidrop and LVDS printed circuit assembly (PCA), as shown in Figure 3-16.
This shunt must be removed from all instruments except that designated as last in the
multidrop chain, which must remain terminated. This requires powering off and opening
each instrument and making the following adjustments:
1. With NO power to the instrument, remove its top cover and lay the rear
panel open for access to the Multidrop/LVDS PCA, which is seated on the
CPU.
2. On the Multidrop/LVDS PCA’s JP2 connector, remove the shunt that
jumpers Pins
21
 22 as indicated in. (Do this for all but the last instrument in the chain
where the shunt should remain at Pins 21  22).
3. Check that the following cable connections are made in all instruments
(again refer to Figure 3-16):
 J3 on the Multidrop/LVDS PCA to the CPU’s COM1 connector
(Note that the CPU’s COM2 connector is not used in Multidrop)
 J4 on the Multidrop/LVDS PCA to J12 on the motherboard
 J1 on the Multidrop/LVDS PCS to the front panel LCD