1. How to determine the model number of the instrument?

Answer: The SKG meter surface film is marked with the instrument type on the lower right side, while the CD (908) series instrument case side label has the meter installed module form, which can determine the instrument host model and the installed module according to the dot mark (but the instrument) If the manufacturer does not ship the product directly, some modules may be installed by the agent or the supporting manufacturer, and there is no mark); in addition, the digital part of the instrument main model and the internal software version number can be displayed when the instrument is powered on; the instrument case can be opened to view the instrument installed. Module; according to the machine number, the instrument model can also be found to the company's Ministry of Commerce.

2. The instrument flashes “OrAL”, or displays “HHH” “LLL”. The meter display is not accurate.

Answer: The symbol “OrAL” “HHH” “LLL” indicates that the input signal exceeds the meter range. Check whether the input sensor is damaged; whether the input wiring is correct; whether the meter input type (SN parameter) setting matches the sensor; whether the meter input range setting is Consistent with the sensor range; whether the translation correction parameter SC (or Pb) setting is correct.

3. Instrument SV, internal parameters cannot be modified? The program table cannot enter the program setting state?

Answer: The parameter lock Lck parameter should be set to 0 to modify the SV or program. If it is the CD series LCK setting 909, all parameters can be modified, but the LOC must not be retained in the 909 after the parameters are modified, to avoid accidental operation and change internal important parameters.

4, the instrument has no output signal, does not work

Answer: Check whether the instrument output wiring is correct; control mode, output mode, output upper and lower limit; whether the SV/block value is set correctly, whether the program table has running program; whether the instrument output module is installed correctly; whether the meter has set alarm external shutdown Features.

5, the relay output action is too frequent

Answer: The output cycle parameter T can be increased. The general relay can be set between 15 and 60 seconds. It can balance the relay life and control effect, but it is recommended that the customer use thyristor or solid state relay for control.

6, PV display value fluctuations

Answer: To check whether the sensor input adopts shielded wire, only the short distance and no interference in the field can use the unshielded wire as input; check whether the sensor works normally; some thermocouples do not do well internal insulation, resulting in the thermocouple negative and outer casing. Collision, except for the use of a leaky thermocouple that requires very fast temperature sensing speeds, it is not recommended to use such a thermocouple with the negative electrode and the outer casing. This type of thermocouple cannot be used for multi-channel measurement common to the negative pole. And if the electric furnace insulation material leaks at high temperature, it will not only cause fluctuations in measured values but also affect system safety. If the measurement speed is not high, the filter parameters of the meter can be set as necessary to appropriately reduce data fluctuations.

7. CD series instrument flashing alarm symbol and alarm indicator light? The alarm light is on but there is no signal output?

Answer: Check if the alarm parameter setting value and AP parameter are correct; if there is an alarm module installed.

8, the instrument control is unstable

Answer: The new watch must be self-tuned once before the new system is used. The instrument also has an adaptive self-learning function. After the tuning is completed, the instrument needs to work for tens of minutes to several hours to enter the optimal working state. If the control has deviation after setting Generally, the self-tuning conditions do not match. You can refer to the instructions on the manual to modify the self-tuning conditions. In special circumstances, you may need to manually modify the PID parameters. For the same system (for example, the same type of electric furnace), the characteristics are generally not much different. Enter the known correct PID parameters without repeating the auto-tuning.

9, CD series instrument heating and cooling options, heating and cooling dual output settings

Answer: The heating and cooling options are achieved by modifying the CF parameters; the heating and cooling dual outputs are defined by modifying the OPL parameters.

10, heating control instrument PV is greater than SV, there is output, uncontrolled

Answer: The control algorithm of the instrument is composed of proportional, integral and differential (ie PID operation). When the PV is larger than SV, it only represents the proportional action part to turn off the output, but the differential action and integral action do not simply see whether the PV is larger than SV, differential Mainly look at the current trend, and the integral is the accumulation of past history, so even if the heating control PV is larger than SV, there may be an output, because the system thinks that this is the only way to avoid excessive PV drop. Of course, if the PV continues to be larger than SV, the error cannot be returned to zero. It may be that the PID control parameters are not set properly and need to be self-tuned or reset. In addition to the above reasons, setting the reaction to positive (system function CF parameter) setting error, output lower limit OPL parameter setting is not 0 will also result in output when PV is greater than SV.