ICP DAS company has introduced remote I/O modules ET-7217RMS and PET-7217RMS with RMS voltage measurement capability. RMS (root mean square) voltage, otherwise called effective voltage, is the value of an alternating voltage at which the load consumes the same amount of current as with a constant voltage. The main difference between the modules is that the PET-7217RMS can be powered via a PoE switch, which makes it possible to power the module and transmit data via a single Ethernet cable.
I/O modules ET-7217RMS and PET-7217RMS have 8 differential analog inputs with the ability to individually configure channels for different voltage measurement ranges. The modules also have 4 digital open collector outputs for load control.
The two Ethernet ports act as a regular unmanaged switch, allowing modules to be daisy-chained. The modules can be controlled, and data received from them via the Modbus TCP protocol. This also allowed to implement the function of pairing modules when the input of the first module is duplicated at the output of the second module. In addition, they have compact palm-sized dimensions and operate in wide temperature range from -25 to +75° C.
Main features of ET-7217RMS and PET-7217RMS
| Name | ET-7217RMS | PET-7217RMS |
|---|---|---|
| Analog input | 8, differential | |
| Voltage range |
0 ~ +10 V rms, 0 ~ +5 V rms, 0 ~ +1 V rms, 0 ~ +500 mV rms, 0 ~ +150 mV rms |
|
| Resolution | 16 bit | |
| Margin of error |
50/60 Hz ±0.15% of the range 45 Hz to 10 KHz ±0.5% of the range |
|
| Samples per second | 10 Hz, total | |
| Individual channel configuration | Yes | |
| Digital output | 4, open collector | |
| Maximum current load | 700 mA per channel | |
| Voltage | 5…50 V DC | |
| Ethernet ports | 2 x RJ-45 in switch mode | |
| Ethernet isolation | 1500 V DC | — |
| I/O isolation | 2500 V DC | |
| Power requirements | 12…48 V DC | |
| PoE power | — |
Yes, IEEE 802.3af, Class1 |
| Protocol | Modbus TCP, Modbus UDP | |
| Dimensions | 120 x 76 x 38 mm | |
| Operational temperature | -25…+75°C | |
