Vicor FlatPAC-EN MI EN Compliant Autoranging Switchers User Manual
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Signal Ground on CBJ1-1 is an isolated secondary ground reference for all CBJ1 interfacing signals. This is not
the same as Earth Ground on input power connector MBJ1.
AC OK (CBJ1-3)
AC OK is an active high TTL compatible signal and provides a status indication of the AC input power. It is on pin
CBJ1-3 and is capable of sinking 16 mA maximum. This signal switches to a TTL "1" when the high voltage bus
exceeds low-line condition during turn-on. Upon loss of input power, the bus voltage will drop, causing the AC
OK signal to go low. Typically, a 2.5ms holdup time is provided for a 500W load following the loss of the AC OK
signal.
TRANSMIT/RECEIVE RS-232 Command Protocol (CBJ1-4 and CBJ1-5)
The FlatPAC-EN/EN MI incorporates a microprocessor for communicating status and allowing user control. A
suitable Terminal Emulator must be used to communicate with this circuit. A free emulator can be downloaded
from the vicor website at www.vicorpower.com (FlatPAC-EN page). Operation in the remote mode requires com-
manding the Power Supply to be a slave via the RS-232 interface.
Operating Modes
The FlatPAC-EN has two operating modes, Remote and Manual, which can be set using the RS-232 interface fea-
ture. The operating mode setting is stored in a non-volatile EEPROM and requires an REON or REOFF command
in order to switch modes. The default mode setting from the factory is in Manual mode. The FlatPAC-EN has an
operating mode indicator LED, which is viewable through the left side vent hole nearest the CBJ1 E/D Interface
Connector. When this LED is ON, the power supply is operating in Remote Mode.
Communications Protocol
The protocol is an ASCII character stream that will be sent back and forth between the power supply and the user.
The FlatPAC-EN/EN MI in the remote mode will be considered a slave in that it will only respond to commands
and requests and will not initiate conversations. Communications are half-duplex in that only the FlatPAC-EN/EN
MI receiver or transmitter may be active at one time. The unit will reply to all commands or requests with a
defined response followed by a carriage return and line feed character pair (CR/LF). The user must wait for the
reply from the FlatPAC-EN before issuing the next command or request. The data bytes will have a format of 1
start bit, 8 data bits, 1 stop bit and no parity at 9600 Baud.
Commands, Status Requests and Module Replies
All commands and requests will have a reply. The reply will be one of the following character strings followed by
a CR/LF character pair. "OK"- Issued when a command has been received and acted upon and the command has no
return data associated with it. "Inv Command"- Issued when an unrecognized command has been received or a
command cannot be executed at this time. "Inv Range"- Issued when a command argument is not within a valid
range.
The following is the list of commands and their definitions. All commands must be followed with a CR/LF charac-
ter pair.
PUP - Power Up
This command starts the automatic turn on timed sequence for the modules. If a Power Down sequence is active at
the time this command is received, a reply of "Inv Command" is returned; otherwise "OK" is returned.
PDN - Power Down
This command starts the automatic turn off timed sequence for the modules. This command can be given at any
time and will cancel any uncompleted automatic power up sequences. "OK" is returned.
EMO - Emergency Off
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Vicor 800-735-6200 Westcor Division 408-522-5280 Applications Engineering 800-927-9474
03-000050 rev A
FlatPAC-EN/EN MI Design Guide
LED Indicator inside
CBJ1
Interface
Connector
Output
Connections
Figure 4: LED Indicator