Delta DTM Series - Multi-Loop Control Function; Enable Multi-Loop Control Function

Chapter 6: Operating Instructions for Other Auxiliary
Functions
DTM temperature controller operating manual
6-11
6.4 Multi-loop control function
The multi-loop control function provides users with the option of controlling multiple sets of outputs with one
master loop, which can save a large number of sensors and complicated wiring in specific applications.
After the user switches the DTM host to the multi-loop control function mode, the original standard mode is
no longer applicable to the output setting and control mode of the output expansion module, and special
output setting and control mode will be used.
DTM multi-loop control system configuration composition, in addition to the measurement host or
measurement expansion modules, can use 8-point output expansion modules DOV, DOR, DOC, DOL or
16-point output DOX module.
When all output expansion modules only use DOX modules, the DTM system allows the number of output
expansion modules to 15; if the output expansion module uses any 8-point output modules, the DTM system
only allows the number of output expansion modules to 8.
In the multi-loop control mode, the expansion cassette output of the measurement host or the expansion
cassette output of the measurement expansion module will default to the output corresponding to each input
channel of the device, and the multi-loop control setting method is not applicable.
The following multi-loop control setting methods are only applicable to output expansion modules, including
DOV, DOR, DOC, DOL and DOX.
Multi-loop control function is divided into auto multi-loop control mode and manual multi-loop control mode:
In auto multi-loop control mode, the user must fill in four parameters MaxSV, MinSV, temperature
difference coefficient, main control coefficient, auxiliary control coefficient and auxiliary SV value of
each point. The DTM system will automatically calculate the appropriate auxiliary output percentage for
each point to control the temperature of each point.
The manual multi-loop control mode requires the user to fill in the auxiliary output percentage of each output
point, and then adjust it repeatedly according to the application status of the field device.
6.4.1 Enable Multi-loop control function
The DTM system is preset to the standard mode at the factory. To use the multi-loop control mode, you
must first enable the multi-loop control parameters.
A. Write 746C to X25CH address to enable DTM special function.
B. Write 0008H (automatic multi-loop control) or 0002H (manual multi-loop control) to the address of
X1E6H. X is the internal station number of the measurement host or measurement expansion module:
Table-Hx1E6 function setting communication content definition
 Note: x indicates internal station number.
 Note: When b1 and b3 are both 1, b3 will be automatically set to 0.
Note: When the user enable the multi-loop control output function, the following functions will be disabled,
1. Self-definition of Functions (Default)
2. Programmable control.
3. Multi-group PID parameter switching.
4. Heating and cooling control.
Hx1E6
Communication
Address
b7 b6 b5 b4 b3 b2 b1 b0
Don’t
care
Don’t
care
Don’t
care
Don’t
care
Auto multi-loop Alarm disable at STOP
Manual
multi-loop
Stop at
power ON