Programmable Serial-to-Ethernet Device Server
PDS Series User Manual, Version 2.5, Mar. 2019
-
171 -
Digital Output
The output status of the module has three different conditions:
1.
Safe Value
: If the Host Watchdog Timeout status is set, the output is set to the Safe Value. If
the module receives an output command, such as @AA(Data) or #AABBDD, the module will
ignore the command and return ‘!’, and will not change the output to the output command
value. The Host Watchdog Timeout status is set and store into EEPROM while the Host
Watchdog Timeout interval has expired, and can only be cleared by setting the command
~AA1.
If user needs to change the output, the Host Watchdog Timeout status needs to be cleared
first, and an output command need to be sent to change the output to the desired value.
2.
PowerOn Value:
Once the module is reset, and the Host Watchdog Timeout status has been
cleared, the output of the module is set to a predefined Power On Value.
3.
Output command value:
If the Host Watchdog Timeout status is clear, and the user issues a
digital output command, to the module to change the output value, such as @AA (Data) or
#AABBDD, the module will respond “success” (receive >).
Latch Digital Input
If, for example, the user connects a key switch to the digital input channel and wants to read the
keystrokes, the key input is a digital input pulse, and the keystroke will be lost. By using command
$AA6 to read the A and B positions, the response would be that there was
no keystroke and the keystroke information will be lost. The read latch-
low digital input command, $AAL0, will solve this problem. When issuing a
$AAL0 command at the A and B positions, the response will denote that there is a low pulse
between A and B position signifying a keystroke.
