4.3.TTL Outputs
TTL outputs are provided for process control. High and Low set points are entered on the front panel (see Section 3.4) and TTL signals are generated on the I/O cable in the following manner:
1.When the pressure as indicated by the Model 2002 is above the High set point, the High signal line (pin #3) will be set to a TTL high level (+5 VDC). When the indicated pressure is below the High set point, the High signal line (pin#3) will be set to a TTL low level (+0 VDC).
2.When the pressure as indicated by the Model 2002 is below the Low set point, the Low signal line (pin #4) will be set to a TTL high level (+5 VDC). When the indicated pressure is above the Low set point, the Low signal line (pin #4) will be set to a TTL low level (+0 VDC).
These TTL signals are used for a variety of applications. With these signals, the user has the capability to turn off/on various equipment such as valves, flow controllers, pumps, heaters, and safety equipment.
4.4.Power Entry Module
The AC power for the Model 2002 enters the instrument through a power entry module that contains a fuse, on/off switch and an IEC 320 power inlet.
The fuse is rated for 250 V, 1/4 A. It can be accessed by unplugging the AC cord and prying the fuse compartment open with the tab and slot in the power inlet chamber. There is a spare fuse in the compartment within the fuse holder.
Model 2002
Rear Panel Detail
Fig 4.2
TRANSDUCER CONN. | STANDARD |
(FEMALE) | I/O CONNECTOR |
A
nalog
1Analog Out 1 (1024 Torr) High
2Analog Out 1 (1024 Torr) Shield
3Analog Out 1 (1024 Torr) Low
7Analog Out 2 (1000 mTorr) Low
8Analog Out 2 (1000 mTorr) High
9Analog Out 2 (1000 mTorr) Shield
Pin# | Connection |
1 | |
3 |
8
7
SENSOR CONNECTOR
Pin# Connection
1Sensor
2Bridge (sense)
3
4Reference
5Common
6Common (sense)
7N/C
8N/C
I/O CONNECTOR
Pin# Connection
1Analog Output
2Analog Common
3High Setpoint
4Low Setpoint
5Digital Common
6Remote Zero
7+5V
Model 2002 Vacuum Gauge | Page 16 of 37 |
