Novatech 409B Instruction Manual page 11

8.0 Appendix A. Table Mode Details.
8.1 The Model 409B contains on-board static RAM
capable of storing up to 32,768 profile points. Each
point contains phase, frequency, amplitude and
dwell time information. The on-board microcom-
puter reads this RAM and programs the DDS ASIC
per the profile point data. The profile can be set to
loop continuously or to hold at the last point, until
interrupted by a subsequent command.
Only Channels 0 and 1 can be set with the table
8.2 The table mode is toggled on and off by an 'M
t' command from the serial port and executes cus-
tomer provided profile points. 'M 0' always turns
off the table and returns to single tone mode. The
409B starts execution of the profile immediately
upon a receipt of 'M t' following an 'M 0'.
8.3 The command sequence (bold) is of this form
(comments after the ';' are not sent to the 409B, but
are here for explanation purposes):
M 0
;turns off running table mode
t0 0000 aabbccdd,eeff,gghh,ii
;F0 profile point 0, on output 0
t1 0000 aabbccdd,eeff,gghh,ii
;F1 profile point 0, on output 1
t0 0001 aabbccdd,eeff,gghh,ii
;F0 profile point 1
t1 0001 aabbccdd,eeff,gghh,ii
;F1 profile point 1
...
t0 3fff aabbccdd,eeff,gghh,ii
;F0 profile point 0x3fff
t1 3fff aabbccdd,eeff,gghh,ii
;F1 profile point 0x3fff
M t
;begin execution of table
;'0000' two byte RAM address, T0 and T1 must
be paired with same address
;'aabbccdd' four bytes frequency, hexadecimal,
MSB first, 4 bytes. 0.1Hz resolution on LSB
NOVATECH INSTRUMENTS
NOTE:
mode.
;'eeff' phase offset, hexadecimal, MSB first,
only 14-bits active, top two bits are ignored
;'gghh' amplitude scale, MSB first, only 10-bits
active. Amplitude is scaled per above.
;'ii' dwell time, MSB first, in increments of
100µs. 0x00=loop back to start, 0xff=hold present
setting. Each T0-T1 pair must have the same dwell.
8.4 The ',' (comma) in each record is used as a
delimiter and must be included as shown. The inputs
are not case sensitive. Subsequent 'M
mands will toggle the execution of the table on and
off. Upon execution of the table, the output will
always begin with address 0000 and progress until it
encounters an 0xff or 0x00 in a dwell position. The
last record in a table mode will be executed for
100µs if the dwell is set to 00.
Each record must be terminated with an 0x00 or 0xff
in the dwell position to indicate the end of your data.
8.5 The current values stored in RAM can be read
back by the "Dn aaaa" command. N=0 or 1 and
"aaaa" is the address.
8.6 The RAM table is backed-up by a "supercap"
for a minimum of 10 minutes. This allows for short
power interrupts without losing the table informa-
tion. (Consult factory for battery backup options).
8.7 Other Modes. The 409B can be programmed
by using the "B" command to perform many other
outputs. The "B" command can be used to gain con-
trol over the on-board AD9959 DDS ASIC. Refer to
the Analog Device data sheet for detailed informa-
tion when using the "B" command.
8.8 See AN003 for the Model 409B/01 which
includes a variable pulse width (variable symmetry)
output option.
11
t' com-
NOTE:
409B Manual, 17-Apr-2015