The front end recognizes the properties Setting, Basic Status, Basic Control, and Digital Alarms. The Reading and Analog alarm properties, if they exist, are assumed to be attached to a separate A/D readback.
The SSDN for all four properties for the 159 card looks like this:
| 0 | 0 |
| 0 | OID = 47 (hex) |
| crate | slot |
| 47 (hex) | channel |
The Setting property is a one word long two's complement number. It is translated into an F(16)A(0) command to write the DAC value. Reading-the-Setting returns this value, obtained by F(0)A(0).
The Basic Status property reads the F(1)A(0) status and returns it in a single word without alteration.
The Digital Alarm property applies its mask and nominal to the same single F(1)A(0) status word.
Basic Control options are triggered by code words. The front end usually uses the first three codes for parameter page and digital status page Off, On, and Reset respectively. That convention is followed here. The other codes are present because they were requested for completeness.
Code Camac Func Action 1 F(28)A(0) P.S. OFF 2 F(30)A(0) P.S. ON 3 F(12)A(0) P.S. RESET 4 unused 5 unused 6 F(9)A(0) 159 card reset 7 F(24)A(0) Disable pulsed input 8 F(24)A(1) Disable data (force output to 0) 9 F(26)A(0) Enable pulsed input 10 F(26)A(1) Enable data