User manual

Instrument Connection 4
User Manual 31
1 Turn off the power to both the 35900 and the instrument containing the
remote start/stop contacts.
2 For instrument-specific cables–Connect one end of the cable to the
instrument's remote control connector using the instrument manufacturer's
instructions.
For general purpose cables–Use the pin assignments shown in
Appendix A, and the instrument manufacturer's instructions to connect the
wires to the instrument's remote control contacts. See also Table 8. The
following notes apply to a general purpose connection:
START and
STOP lines are used for both input and output. As input, a
10 ms or longer pulse of TTL low(<0.8 V) is required. As output, a 120 ms
TTL low pulse is sent.
READY line is both input and output. TTL low indicates not ready.
POWER ON line is shorted to ground when power is off. It is TTL high
(>2 V) when power is on.
3 Connect the cable to the appropriate (A or B) remote control connector on
the rear of the 35900.
4 If needed, repeat for the other channel.
Ta bl e 8 Remote control bus pin definitions
Pin Signal name Description
1 Digital Ground
2 Prepare
*
Pulsed low to request prepare for analysis (for example calibrate detector, turn on lamp,
etc.).
3 Start* Pulsed low to signal that run has started (begin integration, temperature program, etc.)
4 Shut Down Low level indicates that system has a serious problem (for example leak: stop pump).
5 Reserved
6 Power On High level indicates that all instruments connected to the system are switched on.
7 Ready High level indicates that system is ready for next analysis (sequence may continue).
8 Stop* Pulsed low to signal end of run: all modules should go to ready state as soon as possible.
9 Start Request* Pulsed low to request start of injection cycle, (autosampler signals START at time of
injection).
* Input signals must be TTL low pulses (or contact closures to ground) with a duration of at least 10 ms; output signals are
TTL low pulses with a duration of approximately 120 ms.