Yes, these two input modules look pretty similar at first glance. Both of them feature 8 universal inputs for various analog signals, i.e., from current or voltage transmitters, temperature sensors, and other devices with standard analog outputs. Each input of both modules can be configured for the required signal. This allows communication with various sensors or transmitters with a single module without the need to purchase multiple modules, which are usually available separately for each signal type. This feature makes these modules a valuable and cost-effective tool in automation systems.
Despite many similarities, the MV110-24.8A and MV110-24.8AS extension modules have some differences. The most important are:
- - Support for temperature sensors. The 8A supports a variety of RTDs and TCs. The 8AS does not support any temperature.
- - Different sampling times of the inputs. When comparing the standard current and voltage inputs of the MV110-24.8A and MV110-24.8AS extension modules, the difference in sampling time per input is significant. It takes 5 ms for the input of the 8AS to sample a value of the signal. The 8A needs 0.6 s (600 ms) to do the same.
- - Support for digital signals. The 8A can be configured for digital signals, the 8AS however, does not support digital signals. For this reason, the MV110-24.8A input module is particularly useful when the system contains several digital signals in addition to analog signals, and the purchase of an additional digital module seems economically unreasonable.
- - Support for resistive position sensors. The 8A can operate with 900 ohm or 2 kohm position sensors, in contrast, the 8AS can not work with resistive sensors.
- - Support for different types of voltage signals. The 8A can process signals from 0-1 V or -50 ... +50 mV, and the 8AS only 0-10 V.
| MV110-24.8A | MV110-24.8AS | ||
| General | |||
|---|---|---|---|
| Power supply | 24 V DC | ||
| Power consumption, max. | 6 W | ||
| Analog inputs | 8* | 8 | |
| Input signal | RTD (see User Guide for the complete list) | —//— | |
| TC (see User Guide for the complete list) | —//— | ||
| 0(4)-20 mA (sampling time per input 0.6 s) | 0(4)-20 mA (sampling time per input 5±2 ms) | ||
| 0-5 mA (sampling time per input 0.6 s) | 0-5 mA (sampling time per input 5±2 ms) | ||
| 0-10 V (sampling time per input 0.6 s) | 0-10 V (sampling time per input 5±2 ms) | ||
| 0-1 V (sampling time per input 0.6 s) | —//— | ||
| -50...+50 mV | —//— | ||
| 25...900 ohm | —//— | ||
| 25...2000 ohm | —//— | ||
| Resolution | 16 bit | 10 bit | |
| Communication | |||
| Interface | RS485 | ||
| Protocol | Modbus RTU / ASCII | ||
| Baud rate | 2.4...115.2 kBit/s | ||
| Environment | |||
| Ambient temperature | -20...+55 °C | ||
| Storage temperature | -25...+55 °C | ||
| Humidity | up to 80%, non-condensing | ||
| IP Code | IP20 | ||
| Enclosure | |||
| Dimensions | 63 x 110 x 75 mm | ||
| Weight | approx. 240 g | ||
| Material | plastic | ||
*can be configured for digital signals
Making the choice
If you only need to process standard current signals of 4-20 mA, 0-20 mA, 0-5 mA, or voltage signal of 0-10 V, it is better to take advantage of the shorter sampling time of the MV110-24.8AS' inputs.
In other cases, for example, if you need to process 0-1 V or -50...+50 mV signals, or if you require a combination of digital and analog inputs, or signals are processed by RTDs or TCs temperature sensors, then the input module MV110-24.8A is the way to go.