High Voltage/TSP Filament Interlock Option
The remote interlock allows disabling of the high voltage outputs or TSP filament firing (if TSP
option is installed). The interlock is installed at
J506
(on the back panel of the MPC) if the
option is installed.
Figure III-11. Line drawing of the optional interlock connector J506.
The interlock is configured to enable both high voltage outputs when the loopback plug (PN
380082) is attached. The user may install external interlock switches using the extra connector
kit provided with the interlock option. To enable high voltage: short pins 1 to 3 and 7 to 9 for
output one and output two (if available) respectively. To enable the TSP (if installed): short pins
2 to 4 and 6 to 8.
Serial Interface
TIA/EIA RS-232/422/485 are electrical standards specifying hardware requirements for a serial
communications interfaces. The standard specifies a bi-directional (half duplex), multi-point
interface, allowing multiple devices to be connected to the same serial port on a computer. The
standard does not set up or address any software protocols. A carefully planned protocol for use
between the remote devices and the controlling computer allows devices manufactured by
different companies to function on the same port, even if they do not use the same protocol. This
section lays out a standard protocol for use on any future PHI (Physical Electronics) instruments
that use the standard, and makes recommendations regarding hardware design in areas where
software performance may be affected.
Standard
The interface consists of a differential (balanced) twisted wire pair that is connected to all
devices on that serial port. This makes the interface fairly immune to electrical and RF (radio
frequency) noise generated in the vicinity. All units on the same port must be configured for the
same baud rate.
Devices cannot send data until they have been addressed by the controlling computer. A typical
command exchange for a device would be:
1.
The computer sends a command.
2.
Devices read the address.
Digitel MPC Manual
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