The conductor resistance of 1)+3)+4) or 2)+4) must be 2k or less.
Also, the difference between the conductor resistance values 1)+3) and 2) must be 10 or less.
Figure 3.1 3-wire type
Figure 3.2 2-wire type
Internal circuitInternal circuit
A1
Internal circuitInternal circuit
3 - 4
3.1 Performance Specifications 3.1.2 Conversion speed3 SPECIFICATIONS
3.1.2 Conversion speed
The conversion speed of the ST1RD2 is 80ms/1 channel.
3.1.3 Intelligent function module processing time
The ST1RD2 intelligent function module processing time is (CH1 conversion speed) + (CH2 conversion speed).
For the input transmission delay time, refer to the following.
MELSEC-ST CC-Link Head Module User’s Manual
3 SPECIFICATIONS
3.2 Functions
3.2.1 Function list
3 - 5 1
OVERVIEW
2
SYSTEM CONFIGURATION
3
SPECIFICATIONS
4
SETUP AND PROCEDURES BEFORE OPERATION
5
GX Configurator-ST
6
PROGRAMMING
7
ONLINE MODULE CHANGE
8
COMMANDS
3.2 Functions
This section explains the functions of the ST1RD2.
3.2.1 Function list
Table 3.3 lists the functions of the ST1RD2.
Table 3.3 ST1RD2 function list
Item Description Reference
section
Temperature conversion function
(1) This function allows conversion of a "temperature input value" input from a platinum RTD into a temperature data.
(2) Temperature data are 16-bit signed binary (-2000 to 8500) and stored into word input area.
Section 3.2.2
Conversion enable/
disable function
(1) This function specifies whether temperature conversion is enabled or disabled on each channel.
(2) Processing time can be reduced by enabling or disabling the temperature conversion.
(3) By default, conversion is enabled for all channels.
[Setting method]
•GX Configurator-ST( Section 5.3 Parameter Setting)
•Dedicated instruction (RDMSG) from the master station
Section 8.5.1 Conversion enable/disable setting write (Command No.: A400H/ 2400H)
-Wr
3 - 6
3.2 Functions 3.2.1 Function list3 SPECIFICATIONS
Temperature conversion system
(1) Sampling processing
Input temperature values are successively converted into digital values and stored as measured temperature values.
(2) Averaging processing
• Time averaging
Temperature values collected from each channel in the specified period of time are averaged and the average value is stored.
• Count averaging
Temperature values collected from each channel for the specified number of times are averaged and the average value is stored.
• Moving average
Temperature values measured for the specified number of times are averaged for each sampling cycle.
(3) Primary delay filter
By a preset time constant, measured temperature values are smoothed.
(4) Averaging process specification and time/count/moving average/time constant setting can be set for each channel.
(5) Averaging processing specification is preset to sampling processing for all channels.
(6) The time/count/moving average/time constant setting is set to 0 by default.
[Averaging processing specification method]
•GX Configurator-ST ( Section 5.3 Parameter Setting)
•Dedicated instruction (RDMSG) from the master station
Section 8.5.2 Operating condition setting write (Command No.: A402H/2402H)
[Time/count/moving average/time constant setting method]
•GX Configurator-ST ( Section 5.3 Parameter Setting)
•Dedicated instruction (RDMSG) from the master station
Section 8.5.3 CH[] time/count/moving average/time constant setting write (Command No.: A404H/2404H)
Section 3.2.3
Disconnection detection function
(1) By this function, disconnection of a platinum RTD or a cable connected to each channel can be detected.
Also, disconnection is detectable for each wire (Wire A, B and b).
(2) Disconnection can be detected on only the conversion-enabled channels.
Section 3.2.4
Conversion setting for disconnection detection
(1) For values to be stored in , CH measured temperature value area in the case of disconnection detection, you can select "Value immediately before disconnection", "Up scale (each measurement range's upper limit value + 5%)", "Down scale (each measurement range's lower limit value - 5%)" or "Given value".
[Conversion setting for disconnection detection]
•GX Configurator-ST ( Section 5.3 Parameter Setting)
•Dedicated instruction (RDMSG) from the master station
Section 8.5.2 Operating condition setting write (Command No.: A402H/2402H)
[Conversion setting value for disconnection detection]
•GX Configurator-ST ( Section 5.3 Parameter Setting)
•Dedicated instruction (RDMSG) from the master station
Section 8.5.3 CH[] time/count/moving average/time constant setting write (Command No.: A404H/2404H)
Section 3.2.5 Table 3.3 ST1RD2 function list(Continued)
Item Description Reference
section
Wr.n Wr.n+1
3 SPECIFICATIONS
SETUP AND PROCEDURES BEFORE OPERATION
5
GX Configurator-ST
6
PROGRAMMING
7
ONLINE MODULE CHANGE
8
COMMANDS
Measurement range selection function
(1) This function allows setting of the measurement range per channel.
(2) The measurement range is selectable from the following.
[Setting method]
•GX Configurator-ST ( Section 5.3 Parameter Setting)
•Dedicated instruction (RDMSG) from the master station
Section 8.3.1 Initial data batch write request (Command No.: 8106H)
Section 8.3.2 Initial data individual write request (Command No.: 8107H/0107H)
-Alarm output function
(1) This function allows alarm output when the temperature exceeds the range specified by the user.
Setting is available for each channel.
(2) Alarm output setting default is No alarm output for all channels.
(3) Set the 4 limit values of alarm output: upper upper limit value, upper lower limit value, lower upper limit value and lower lower limit value.
These are set to 0 by default.
[Alarm output setting method]
•GX Configurator-ST ( Section 5.3 Parameter Setting) Dedicated instruction (RDMSG) from the master station
Section 8.5.2 Operating condition setting write (Command No.: A402H/2402H)
[Upper upper limit value, upper lower limit value, lower upper limit value and lower lower limit value setting method]
•GX Configurator-ST ( Section 5.3 Parameter Setting)
•Dedicated instruction (RDMSG) from the master station
Section 8.5.4 CH[] upper upper limit/upper lower limit setting write (Command No.: A408H, A40AH/2408H, 240AH)
Section 8.5.5 CH[] lower upper limit/lower lower limit setting write (Command No.: A409H, A40BH/2409H, 240BH)
Section 3.2.6
Command (1) By using commands, command parameters can be set, and the parameter
settings can be written from RAM to ROM and read from ROM to RAM. CHAPTER 8 Table 3.3 ST1RD2 function list(Continued)
Item Description Reference
section
3 - 8
3.2 Functions 3.2.1 Function list3 SPECIFICATIONS
Table 3.3 ST1RD2 Function List (Continued)
Item Description Reference
section
Compensation of measured temperature value
(1) The ST1RD2 is capable of correcting the error between "actual temperature" and
"measured temperature", which may occur due to variation in platinum RTD accuracy and/or a specific wiring or grounding condition.
To compensate the error, the 1-point compensation using the sensor
compensation function and the 2-point compensation using the offset/gain setting can be used.
•Sensor compensation function
When the measurement range width is less than 60 , use the sensor compensation function.
The compensation value can be easily obtained in 1-point temperature measurement only.
•Offset/gain setting function
When the measurement range width is 60 or more, use the offset/gain setting function.
Wide-range compensation is available.
(2) For the sensor compensation or the offset/gain setting, prepare a thermometer to measure the temperature of the object.
Compensation is performed based on the difference between the temperature measured by the thermometer and the one measured by the ST1RD2.
-Sensor compensation function
(1) The measured temperature value is compensated based on the set sensor compensation value.
The compensation is available for each channel.
[Sensor compensation method]
GX Configurator-ST
Dedicated instruction (RDMSG) from the master station
Section 8.5.6 Sensor compensation value write (Command No.: A41AH/241AH)
Section 3.2.7
Offset/gain setting function
(1) Linear compensation is available by individually compensating any given 2 points (offset/gain value) within the effective range.
The offset/gain setting can be made for each channel.
(2) To use the user range setting, the offset/gain value selection must be made in advance.
The offset/gain value selection is available for each channel.
Default is set to "factory default".
[Offset/gain setting method]
•GX Configurator-ST
•Dedicated instruction (RDMSG) from the master station
Section 8.6.3 Operation mode setting (Command No.: B402H/3402H) Section 8.6.4 Offset channel specification (Command No.: B403H/3403H) Section 8.6.5 Gain channel specification (Command No.: B404H/3404H) Section 8.6.6 User range write (Command No.: B405H/3405H)
[Offset/gain value selection method]
•GX Configurator-ST ( Section 5.3 Parameter Setting)
•Dedicated instruction (RDMSG) from the master station
Section 8.3.1 Initial data batch write request (Command No.: 8106H)
Section 8.3.2 Initial data individual write request (Command No.: 8107H/0107H)
Section 4.5
Online module change
(1) A module can be replaced without the system being stopped.
[Execution procedure]
•GX Configurator-ST
•Button operation on the head module
CHAPTER 7
3 SPECIFICATIONS
3.2 Functions
3.2.2 Temperature conversion function
3 - 9 1
SETUP AND PROCEDURES BEFORE OPERATION
5
GX Configurator-ST
6
PROGRAMMING
7
ONLINE MODULE CHANGE
8
COMMANDS