No apologies necessary - the sequencer system is complicated to get to grips with. So for an example you want to generate a pulse on pins 1 and 5 of the outputs socket. This corresponds to digital output bits 15 and 7 which is a bit weird so I am going to assume that you meant bits 1 and 5 of the standard digital outputs (which are actually bits 9 and 13 which are on pins 4 and 2). If you do want bits 15 and 7 you would need to use both DIGOUT and DIGLOW which will make things complicated. The code would look like:
The first instruction sets two output bits, the delay generates a wait, and the final instruction clears the two bits. Please note:
The pulse length is generated by the delay between the two instructions as the sequencer executes instructions at a fixed rate. The ms(200) calculates the correct delay count, the -2 adjusts for the time taken for the delay instruction itself and one of the DIGOUTs
These are digital outputs with TTL signals, so they only exist in two states: high and low. Low is close to zero volts, high is usually around 4.5 volts but for digital outputs the actual voltage is relatively unimportant. But you are talking about controlling the voltage, so if you really mean that then you should indeed be using the DACs instead.
Basically I wanted to know if to control a specific pin on the rear panel it was necessary to change the instructions of the sequencer document (for example using the DIGOUT/DIGLOW instructions instead of the DAC instruction to control the electrical pulses generated).
From what you say here, I fear we have been talking at cross purposes because I did not understand you. The 1401 can generate both digital and DAC outputs, these have different characteristics, and are available on different connectors on the 1401 - you cannot change a given physical connector on the 1401 from DAC to digital or anything like that.
DAC outputs and the digital outputs are both available on the front of the 1401 and the back panel but this is just for convenience in wiring things up - the DAC signals on the BNCs are the same as the DAC signals on the rear analogue connector (& similar for digital but different connectors).
So when you use a command like DAC 0,1 you are setting the voltage on DAC number 0, whose output is available on a front panel BNC and on a specific pin on the rear analogue connector. Similarly if you change the state of digital bit 1 this will change the voltage on the corresponding connectors.
I hope that is clear.
So first of all you have to look at what type of outputs you need. Looking back at your first post (with better understanding now), you say you want to use the 4 DACs to control 3 LEDs and a solenoid. DACs are fine for the LEDs, but a solenoid valve will require significant current which will require external electronics. If all you want to do is turn LEDs on and off and open and close the valve then it seems to me that these are all on/off situations and digital outputs can be used (again electronics will be needed for the solenoid) but DACs will be fine. If, however, you were ;looking for TTL signals then you need to use the digital outputs.
As you say two DAC outputs are on the front, numbers 0 and 1, so they are easy to get at. The other two, numbers 2 and 3, are on the rear analogue connector so a bit of wiring there. But crucially (I think this is what you really wanted to know) you would use the sequencer DAC instruction to control all four of these, with different DAC numbers in the instruction to control which DAC (& therefore which connector) is affected.