Nevion FR-2RU-10-2 - Manual (Page 23)

FR-2RU-10-2 Rev. N
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7 Flashlink control protocol
7.1 Document conventions
All commands sent to the card are printed in italics.
This is a command sent to a card.
All responses sent from a card to the controller are printed in bold.
This is a response sent from a card to the controller.
7.2 Hardware interface
The hardware interface is basically RS-422, a serial communication standard much like
RS-232 but with balanced lines. You can use a simple (dumb) RS-232 to RS-422
converter if you want to use a standard RS-232 port (eg. a PC COM port).
The receive and transmit lines can be connected to make a true RS-485 bus, but this
requires special care from the PC side, since you have to control the bus direction (e.g.
using a dedicated RS-485 board with RS-485 drivers). We recommend using RS-422
for control.
Data rate: 115200 bps, 8 bits, with one stop bit and no parity.
All data is 8 bit ASCII (ISO8859-1 encoding, but currently any ASCII encoding will do
since no special ASCII characters are used).
7.3 Addressing
Each card has a unique identifier called card position, which is assigned (trough
hardware pinning) automatically when a card is inserted into a subrack. The card
positions are numbered from 1 to 10 from a user point of view. From a protocol (or
software) point of view, the cards are numbered 0-9. When we refer to card position in
this document, we refer to this "low level id" numbered 0-9, but the user should always
see positions 1-10 in menus, etc.
Each subrack (if you use more than one) should have a unique subrack id, numbered
0-7 (user and protocol/software wise). The id is set by DIP switches on the rear of the
rack, behind the power supply.
7.4 General command structure
Each command is built up of a sequence of ASCII characters terminated by linefeed.
The first two characters are the source adress (source subrack id and the source card
position).
Frame structure:
Byte 0 Rack ID (0-7); Destination
Byte 1 Card position (0-9); Destination
Byte 2 Rack ID (0-7); Source
Byte 3 Card position (0-9); Source
Byte 4
– n
Command or command response
Byte n+1 Linefeed (10 decimal, 0x0A hex)
If the command or command response contains a line feed, it is preceded by a
backslash (\).