MKS 651C, Instruction Manual, Page: 133 / 172

Appendix D: Type 651 Displayless Unit Type 651 Displayless Unit
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Appendix D: Type 651 Displayless Unit
Type 651 Displayless Unit
The displayless unit is a standard 651 unit with the following differences:
•
There is no front panel display
•
An additional RS-232 serial port, located on the front panel, is intended to be used in
conjunction with a laptop or notebook computer
•
The baud rate is set at 9600 with no parity, 8 data bits, 1 stop bit, and [CR][LF]
delimiter
To put the 651 displayless unit into operation via the RS-232 port on the front panel, set the Key
Lock switch to the Local position. When the Key Lock switch is set to the Local position, TTL
input and the rear serial communications port become locked out. Conversely, when the Key
Lock switch is set to the Remote position, the front serial communications port becomes locked
out, and the unit can be controlled either by TTL input or through the serial communications port
on the rear panel.
600 Series
Pressure Controller
Serial Interface
Power
Remote
Local
Figure 14: Front Panel of the 651 Displayless Unit