Bob, a process control engineer, is replacing a digital pressure gauge with a range of 0-80 psi in his control system. The new gauge he just bought has a 0-100 psi range and is equipped with a 4-20 mA output that he plans to wire into his logic controller.
During the installation process Bob realizes that his logic controller and system has been configured to automatically scale the 4-20 mA signal to 0-80 psi (4 mA at 0 psi, 20 mA at 80 psi). Meanwhile, the gauge he just bought is scaled from 0-100 psi (4 mA at 0 psi, 20 mA at 100 psi). Irritated, Bob struggles to program the software in his logic controller and other system components to adapt to the parameters of the new gauge.
It is unfortunate that Bob had to adapt his whole system for just one gauge. It would have been much easier and more efficient if Bob were able to adapt the single gauge to his existing system.
Our digital pressure gauges allow the user to define the pressure values associated with the low analog signal (i.e. 4 mA or 0V) and the high analog signal (i.e. 20mA, 2V, or 5V). So in Bob’s case, he could simply assign the high analog signal (20 mA) to a psi value of 80. This is how you do it:
Double Note: The analog set points must be entered using the gauge’s base unit of measure (typically PSI).
Step 1: Press the On/Off button once to enter the main setup menu.
Step 2: Press (Z) to cycle through the options until Output is displayed.
Step 3: Press (S) to access the Output Settings menu.
Step 4: Press (Z) to cycle through the options until AL SET is displayed.
Step 5: Press (S) to access the Analog Low set point value. A 5-digit number will appear with the first digit flashing.
Step 6: Press (Z) to change the value of the first flashing digit (options: 0-9 or “-“).
Step 7: Press (S) to accept the value of the flashing digit and advance to the next digit. Repeat steps 6 and 7 until the desired Analog Low reading is fully entered. After the last digit is accepted by pressing (S), the display will return to the main options menu.
Step 8: Press (S) to reenter the Output Settings menu.
Step 9: Press (Z) to cycle through the options until AH SET is displayed.
Step 10: Repeat steps 5-7 to enter the Analog High set point value.
Step 11: To exit the output menu, press (Z) until EXIT is displayed and press (S) to exit to the main setup menu.
Remember that adjusting the analog low and high set points will affect the resolution of the analog signal. For example, if you are using a 0-100 PSI gauge with a 0-5V output, and you change the set points from 0 to 15 for the low set point (0V), and from 100 to 85 for the high set point (5V), the resolution of the analog signal will decrease.
If you would like some help, don’t hesitate to give us a call and we will be happy to assist you.