Input Lines; Command Codes; Table 4-2. Command Code Types - Sutter Instrument Lambda DG-4 Operation Manual

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4.1.2 Input Lines

The 8 input lines of the parallel input (data input lines 2-9) are read by the controller as an 8
bit value with input line 9 corresponding to the most significant bit. When the control unit is
in the ON-LINE (remote) mode, the 8 input lines are examined at 50 microsecond intervals.
If the value of the filter or command indicated by the input lines has changed from the
previous time the lines were read, the control unit will set the BUSY line and then respond as
commanded. See the BUSY LINE section for further details about this data line.

4.1.3 Command Codes

All commands to the Lambda DG-4/5 correspond to an 8-bit binary value (not all of the
possible 256 values are utilized). The binary values that are used can be classified in the
following way:
Value range
(Decimal, hexadecimal,
binary)
0 – 15
00 - 0F
00000000 - 00001111
16 - 31
10 - 1F
00010000 - 00011111
32 - 255
20 - FF
00100000 - 11111111
The first 16 binary values (00000000-00001111) are read as "filter change" commands that
take effect immediately (i.e., "MOVE ON COMMAND"). Each one selects the FILTER
NUMBER that corresponds to the command's decimal value (0 to 15). Another way of stating
this is that when the 4 most significant bits of the 8 bit binary value all equal 0 (data input
lines 6-9 are all LOW) the 4 least significant bits (data input lines 2-5) will be treated as a
four place binary number whose decimal value corresponds to the desired FILTER NUMBER
(0-15).
The next 16 binary values (00010000-00011111) are also read as "filter change" commands.
These commands will not be executed, however, until the next "trigger" (STROBE or SYNC
PULSE, depending on the mode that is active) has been detected. Each of these commands
selects the FILTER NUMBER that corresponds to the command's decimal value less 16. If,
for example, you want to select FILTER NUMBER 6 on the next STROBE PULSE, you
would send the binary equivalent of the decimal number 22 (00010110). Another way of
describing these commands is as follows. When the binary value of the three most- significant
bits is 0 (data input lines 9, 8, and 7 are all LOW), and the next least-significant bit's binary
value is 1 (data input line 6 is HIGH), then the four least-significant bits (data input lines 5,
4, 3, and 2) are treated as a 4-bit binary number that corresponds with the desired FILTER
NUMBER (0 - 15).

Table 4-2. Command code types.

MOVE ON COMMAND to the corresponding FILTER
NUMBER (i.e., immediately after receiving the command).
MOVE ON TRIGGER to the corresponding FILTER
NUMBER (move only if triggered by Strobe, Synch, or
Synch gated by Strobe).
Special commands (22 in all)
LAMBDA DG-4 & DG-5 OPERATION MANUAL – REV. 3.05C (20150414)
Command Type