Artifex LDD100-F Series, Original Operating Instructions, Page: 66 / 72

LDD100 Operating Instructions
66 / 72
11.2.1 Pulse Duration
As for the pulse repetition period, the pulse duration is calculated via a base parameter (Byte
3 and Byte 4) as well as a timer (Pulse Width Timer (PWT): Byte 19). If the PWT is set to 0,
the base parameter has a value of 50ns. Thus, for pulse durations up to 2ms, the PWT may be
set to 0 (50ns x 40,000 = 2ms).
For longer pulse durations, the PWT must be set >0 and increments in a resolution of 600ns.
The following algorithm may be used to calculate the pulse width:
1. For PWT=0: pulse duration = ((width-HB x 256) + width-LB) x 50ns
2.
For PWT≥1: pulse duration = ((width
-HB x 256) + width-LB) x PWT x 600ns
Example:
Byte 3 = 10
Byte 4 = 2
Byte 19 = 20
Pulse duration = ((10 x 256) + 2) x 20 x 600ns = 30,744,000ns = 30.744ms.
11.2.2 Pulse Repetition Period
The pulse repetition period = pulse du pulse separation.
The calculation requires the value of the pulse repetition parameter (Byte 1 and Byte 2) as
well as the pulse separation timer (PST) (Byte 20 and Byte 21).
The calculation of the pulse duration has been discussed in the previous subsection. For the
pulse separation, the base period is multiplied by the PST which has a minimum value of 200
leading to a minimum pulse separation of 50ns x 200 = 10µs.
The pulse repetition period is therefore calculated as follows:
Period = (pulse duration) + (pulse repetition x PST)
Example:
Byte 1 = 6
Byte 2 = 5
Byte 3 = 10
Byte 4 = 2
Byte 19 = 20
Byte 20 = 4
Byte 21 = 6
Pulse duration = ((10 x 256) + 2) x 20 x 600ns = 30,744,000ns = 30.744ms.
Pulse separation = ((6 x 256) + 5) x ((4 x 256) + 6) x 50ns = 79,361,500ns = 79.3615ms
Period = 30.744ms + 79.3615ms = 110.1055ms