L1050069A
6
The following table details the functionality of the pins. To connect a third-party external
detector, present an analog differential signal to pins 10 and 11.
Pin
number
Function
Notes
1
Accessory Bus Reset
System reset, normally 5 V but 0 V pulse on
spectrometer power up. Output.
2
0 VL
0 V return for digital circuitry.
3
Accessory Bus Clock
30 7200 Hz TTL compatible signal for Accessory
Bus microcontroller clock drive. Do not pull
more than ±2 mA from this pin. Output.
4
Accessory Bus Abort
Accessory abort to prematurely finish Accessory
Bus command. Output.
5
Accessory Bus serial transmit
(from spectrometer to
external)
TTL compatible serial signal running at 4800, n,
8, 1. Output.
6
Accessory Bus serial receive
(from external to
spectrometer)
TTL compatible serial signal running at 4800, n,
8, 1. Input.
7
0 VL
0 V return for digital circuitry.
8
5 VL
5 V supply for digital circuitry. Do not pull more
than 1 A from this pin. Output.
9
0 VA
0 V analog return for analog circuitry.
10
External differential positive analog detector
signal. ±11 V full scale. Input. See Note 1.
11
EXTDET−
External differential negative analog detector
signal. ±11 V full scale. Input. See Note 1.
12
0 VA
0 V analog return for analog circuitry.
13
+12 VA
+12 V analog for any analog circuitry. Do not
pull more than 100 mA from this pin.
14
−12 VA
−12 V analog for any analog circuitry. Do not
sink more than 100 mA into this pin.
15
TRIG_IN (NOT
IMPLEMENTED, LEAVE
DISCONNECTED)
Trigger in. Not implemented at the present
time. Input.
NOTE:
The differential input signal has a maximum positive value when is at +11 V and EXTDET− is at −11 V. It
has a maximum negative value when is at −11V and EXTDET− is at +11 V. The input impedance is 100
KΩ on each input with reference to 0 VA.
