Caen N1471A - USB-RS485 Communication Protocol

Programmable HV Power Supply
Revision 19
31
n
CAEN
T o o l s f o r D i sc o v e r y
the cali bra ti on is performed and the program a s k s for coeffi cients to be s aved.
Fig. 3.43: Current offset calibration confirmation
3.5 USB - RS485 Communication Protocol
The following Protocol allows to communicate with up to 32 daisy chained modules. The Protocol is based on
commands ma de of ASCII cha racters s trings . The protocol requires firmwa re revis ion 1.0.1 or greater.
3.5.1 Command Format
The Format of a comma nd s tring is the following :
$BD:**,CMD:***,CH*,PAR:***,VAL:***.**<CR, LF >
The fields that form the command a re :
BD : 0..31 module address (to send the command)
CMD : MON, SET
CH : 0..4 (4 for the comma nds related to a l l Cha nnel s )
PAR : (see parameters ta bl es )
VAL : (numerical val ue mus t have a Format compa ti bl e wi th resol ution and range)
3.5.2 Format of response string
Format response in case of error
String
Function (Units)
#BD:**,CMD:ERR
Wrong command Format or command not recognized
#BD:**,CH:ERR
Channel Field not present or wrong Channel value
#BD:**,PAR:ERR
Field parameter not present or parameter not recognized
#BD:**,VAL:ERR
Wrong set value (<Min or >Max)
#BD:**,LOC:ERR
Command SET with module in LOCAL mode
Ea ch string i s termi nated by < CR, LF >
Format response in case of correct command
String
Function (Units)
#BD:**,CMD:OK
command Ok
#BD:**,CMD:OK,VAL:***
command Ok *** = value for command to individual Channel
#BD:**,CMD:OK,VAL:*;*;*;*
command Ok *;*;*;* = values Ch0,1,2,3 for command to all
Channels
Numerical value Field 'VAL' has Format compatible (comma and decimal part) with the resolution and the range
rel ated to the parameter.
Ea ch string i s termi nated by < CR, LF >