83-507-013 Rev. A
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7.10 SINGLE BYTE COMMANDS
7.10.1 General
Single byte commands are commands in which all the necessary data for the supply to act upon
is contained in a single byte. Single byte commands will be executed immediately by the supply.
If the command requires data to be sent to the HOST PC or IEEE Board (see sections 7.10.4 and
7.10.3.1) that response will be transmitted immediately with no delay due to any software over-
head. With the exception of the Disconnect from communications command, section 7.10.3.1,
commands must be sent by the HOST PC or IEEE Board 2 times in sequence for verification. Alll
have the most significant bit, D7, set to a logic 1. A CR, carriage return, character is not included
in a single byte command. The RST command will not change any setting made by a single byte
command.
All Single Byte commands will be executed in 1 ms or less. This does not include any response
sent to the HOST/IEEE Board, which is dependent upon the response length and the serial
transmission speed (Baud rate).
7.10.2 Global commands without response
7.10.2.1
Disable MD Mode (MD MODE OPTION REQUIRED)
Disable is the default condition upon power up. The Hex value of the command is 0xA0. Send
it two times in sequence. All supplies, both the currently addressed supply and all non-
addressed supplies, will disable MD Mode as a result of this command.
7.10.2.2
Enable MD Mode (MD MODE OPTION REQUIRED)
Send to enable Multi Drop Mode. The Hex value of the command is 0xA1. Sent it two times in
sequence. When this command is sent, the supply will set SRQ retransmission to the disable
state; if you wish it to be enabled you must send the enable command. All supplies, both the
currently addressed supply and all non-addressed supplies, will enable MD Mode as a result
of this command.
7.10.2.3
Disable SRQ retransmission (MD MODE OPTION REQUIRED)
Disable is the default condition upon power up. The Hex value of the command is 0xA2. Sent
it two times in sequence. If the supply sends an SRQ it will only sent it 1 time. All supplies,
both the currently addressed supply and all non-addressed supplies, will disable SRQ re-
transmission as a result of this command. All status registers will retain their data when this
command is sent.
7.10.2.4
Enable SRQ retransmission (MD MODE OPTION REQUIRED)
Enable retransmission of SRQs. This is only available when the Multi Drop Mode is enabled
in the supply. The Hex value of the command is 0xA3. Send it two times in sequence. If the
supply sends an SRQ it will be repeated on a timely basis, 10 ms plus 20 ms times the supply
address, until answered. All supplies, both the currently addressed supply and all non-
addressed supplies, will enable SRQ retransmission as a result of this command.
7.10.2.5
Enable FLT Bit in the SENA Register
The Hex value of the command is 0xA4. Send it two times in sequence.
