X2364 MANUAL
18
118044-001 REV E
Digital Monitor Signals sent from Spellman Power
Supply to Customer Computer:
1.
Cooling Fault (1 = fault)
2.
Overcurrent Fault (1 = fault)
3.
Overpower Fault (1 = fault)
4.
Overvoltage Fault (1 = fault)
5.
Arc Fault (1 = fault)
6.
Regulation Error Fault (1 = fault)
7.
Interlock Status (0 = closed, 1 = open)
8.
Local/Remote Control Mode Indicator
(0 = local, 1 = remote)
8.2 Command Structure
The general operation of the data link is described in this
section.
The Customer computer can send three possible
commands to the Spellman power supply:
SET POWER SUPPLY (S)
command
QUERY POWER SUPPLY (Q)
command
SOFTWARE VERSION LEVEL REQUEST (V)
command.
The
SET
command contains a total of 18 bytes and
instructs the power supply to change any or all of its
control signals. The power supply may execute the Set
command and respond with a simple 2 byte
ACKNOWLEDGE (A) packet, or, if errors are detected,
the power supply will not execute the Set command but
will return a 5 byte ERROR (E) packet.
A
Query
command contains a total of 5 bytes, and is used
to request that the power supply return an information
packet containing analog and digital information that it
monitors. The power supply responds by sending back a
16 byte RESPONSE (R) packet.
In response to a 5 byte Version Request command, the
power supply will return a 6 byte
SOFTWARE
VERSION LEVEL RESPONSE PACKET (B)
packet
to the computer.
For all three commands, if communication errors or
illegal conditions are detected by the power supply, the
command will not be executed and the appropriate 5 byte
ERROR (E)
packet will be sent back to the computer.
8.2.1 Set Command (“S”) and
Acknowledge (“A”) Response
Prior to sending a Set Command that performs any
function other than a Power Supply Reset, the computer
should ensure that no fault conditions are existing within
the power supply. This is done by first sending a Query
Command and examining the returned Response Packet.
BYTE #
DESCRIPTION
1
Start of message character
(“SOH” character; hex 01)
2
Command Identifier Character
(S character, hex 53)
3-5
Voltage Command
(0-60kV corresponds to 0-FFF hex)
6-8
Current Command
(0-15mA corresponds to 0-FFF hex)
9-11 000
hex
12-14 000
hex
15
Digital control data
(X-ray ON, X-ray OFF Power Supply
Reset)
16-17
Modula 256 Checksum of all previous
bytes except start Character
18
End of message character
(carriage return, hex OD)
TABLE 8.3 SET Command Byte Contents
Note that it is legal to send a SET command that does not
assert either of the digital controls (X-ray On or X-ray
Off). For example, if X-rays were in and it was desired to
change one or more of the two analog controls, a
command packet could be sent containing the new values
for the analog controls but with the digital control bits set
to 0. In this case, the analog values will be changed and
X-rays will remain on.
If one or more of the six digital fault monitor signals
(signals 1 through 6 listed under “Digital Monitor
Signals…” of section 8.1.1) are active, the Set command
packet must include a Power Supply Reset assertion.
The
Set
Command is only valid when the power supply is
set to the Remote Mode.
