Operations involving contact input/output in digital indicating controllers are generally carried out with predetermined terminals and functions. (Ex.: Contact output DO1 = Alarm1, etc.). When setting up systems, this can be inconvenient in terms of managing the wiring and peripheral devices (such as PLC's).
The contact input and output functions on the UT551 and other Yokogawa controllers ship with factory defaults, but can be changed by the user as parameters.
The following is an example of changing settings assigned to contact output DO.
In the case of the UT551, "DO1 = Alarm1" is set as an initial value. The terminal numbers are 6 and 7. Likewise, Alarm2 is assigned to DO2 (terminals 5-7, terminal number 7 is the COM terminal).
Normally, to have two outputs of Alarm1 sent to an upstream device, it was necessary to add a relay to the DO1 output and configure the outputs using ladder software inside a PLC.
Now, with the UT551, in cases such as when Alarm2 output is not used, you can output Alarm1 from the DO2 terminal as well.
Stating this in terms of parameter settings:
| |
|
Parameter |
Setting (Initial Values) |
| |
Terminal no. 6-7 |
DO1 |
5689 (Alarm1) |
| |
Terminal no. 5-7 |
DO2 |
5690 (Alarm2) |
If the DO2 setting is changed from 5690 to 5689, DO1 and DO2 both turn ON when Alarm1 occurs.
In addition, the terminal numbers can be changed to output Alarm2 from DO1, Alarm1 from DO2, and other configurations. Also, because the UT551 has relay contact and transistor contact, Alarm1 can also be electrically output from DO4 (transistor contact) rather than DO1 (relay contact).
In the case of contact input, the controller's AUTO/MANUAL switching is assigned to DI1 with a status of ON for MAN and OFF for AUTO, but this setting can also be reversed.
Such contact input/output related setting changes can be easily implemented, making it easier to connect with upstream devices.
Supporting models: UT520, UT550, UT551, UT750, UP550, UP750
Note that only the UT551 supports DI edge switching/reverse status switching.
