AC2520 - Electronic module IFM - Free user manual and instructions

USER MANUAL AC2520 IFM

• Conversion of measured values for 4 channels: 480 ms

• The Pt100 sensors are connected via M12 connection cables.

• Connection of 2-wire / 4-wire sensors possible

• Maximum number of modules per AS-i system: 31

• special features AC2570: stainless steel screws, Viton sealing Installation/Addressing When you use module lower parts without addressing socket (AC5000 or AC5001) first address the module by placing it onto an addressing unit (AC1144) and assign a free address between 1 and 31. When you use module lower parts with an addressing socket (AC5010) the modules can be addressed with the addressing adapter E70213 later on. Mount the module onto the wired module lower part of the AS-i net- work, tightening torque 0.8 Nm. As an alternative FC/FC-E lower parts with earthing lead (AC5020...AC5023) can be used to increase the noise immunity. 7Electrical connection The analogue module is connected to the AS-Interface via the stan- dardised EMS [(supply from AS-i) (also in this case the Pt100 sensors are supplied from the AS-i voltage)]. For all the following wiring diagrams the indicated pin connection refers to the analogue module. Connection of a 2-wire Pt100 element to the AS-i module

4x LED yellow analogue inputs M12 socket label LED green PWR LED red FAULT LED Infrared reciever fixture infrared adapter Pin 1: S + Pin 2: AI + Pin 3: S - Pin 4: AI - Pin 5: screen (functional earth)Connection of a 4-wire Pt100 element to the AS-i module 4-wire Pt100 sensors supply more exact results than 2-wire sensors provided that the wire resistance is the same. The changeover between 2- and 4-wire sensors is made via the para- meter bit P3. Important notes regarding Pt100 measurements: In the Pt100 measurement principle, very low currents flow in the mea- suring electronics. It must be ensured that additional resistance (cables, contact and transition resistance, loose contacts, etc.) is avoided in the measuring circuit. Only this way is a precise measurement, for which these modules are designed, possible. In detail: A 4-wire measurement always has to be preferred over a 2-wire mea- surement. In 2-wire measurement all transition and connection resi- stances add up and may massively falsify the measurement result. Therefore a 2-wire measurement is not recommended! High-quality plugs should be used for the AS-i AC2520 Pt100 module. Prewired and potted plugs with gold-plated contacts should be prefer- red.

Pt100Parameter setting of the analogue modules Activation of the periphery fault message of the channels 1 to 4 According to the table above the parameter bits P1 and P2 are used to define which measuring channels can trigger a periphery fault message. But irrespective of the defined parameters all 4 channels are always transferred via the AS-Interface. It is necessary to connect at least one Pt100 sensor before switching on the AS-i slave to start the A/D converter, otherwise the LEDs I1 to I4 flash at a frequency of about 5 Hz. Operation Check the safe functioning of the unit. Display by LEDs:

• LEDs yellow AI1 ... AI4 on: analogue signal in the measu- ring range flashing: analogue signal outside the measuring range

selection Pt100 elements 2-wire mode 4-wire mode

filter 50 Hz filter in the A/D converter active 60 Hz filter in the A/D converter active The 50 Hz filter applies to the whole of Europe

Periphery fault can be triggered by

on off off off on on off off on on on off on on on on

• periphery fault A periphery fault is indicated if at least one of the signals AI1, AI2, AI3 or AI4 is outside the measuring range or if nothing is connected to at least one analogue channel. Measuring range of the Pt100 module For the measuring ranges, the LED states and their meaning please see the following table: Transmission time of the analogue values The transmission time of the analogue values depends on the conver- sion time of the analogue signals into digital signals in the AS-i module and on the transmission time via the AS-Interface. The conversion time for 4 Pt100 signals is 480 ms. The transmission time of the 4 16-bit values via the AS-Interface ideally is 7 AS-i cycles per value. For a cycle time of 5 ms per AS-i cycle this results in a transmission time of 4 x 7 x 5 ms = 140 ms via the AS-Inter- face. Thus the total transmission time for 4 temperature values ideally is 480 ms (conversion time) + 140 ms (transmission time) = 620 ms.