This tech note describes the process to connect an Endress Hauser Promag 400 flow meter transmitter with a Rapidlogger system. The Promag 400 has passive frequency outputs which sometimes cause confusion as to the proper connection technique when interfacing with the Rapidlogger System.
The Frequency outputs on the Endress Hauser Promag 400 are of the passive type. What this means is that they do not generate any voltage on their own but rather interrupt the flow of voltage being passed through them.
The flow rate output of the Endress Hauser unit is generally configured to be on its Frequency output. On the Endres Hauser the measured variable that is assigned to the frequency output should be “Volume Flow”. The pulse/pause ratio should be setup to the default value “1:1”. The output frequency should be set to the default value of “10000Hz”. The dampening should be set to the default value of “1sec”.
If the user wants to feed the E-H frequency signal to the Rapidlogger Units Frequency input then the connection should be wired as shown in Table 1.
| EH Wire Terminals | Rapidlogger Wire Terminals | |||
| 24 | Passive Frequency + | TB1–3 | 24V DC out | |
| 25 | Passive Frequency - | TB1–20 | Frequency 1 Input | |
| 2 | Ground | TB1–8 | DC Ground | |
Table 1: Promag 400 wired to Rapidlogger Frequency Input
If the user wants to feed the E-H frequency signal to the Rapidlogger Quadrature input then the connection should be wired as shown in table 2.
| EH Terminal | Rapidlogger Terminal | |||
| 24 | Passive Frequency + | TB1–16 | Q1A Input | |
| 25 | Passive Frequency - | TB1–8 | DC Ground | |
| 2 | Ground | TB1–8 | DC Ground | |
| 1 | Power In | TB1–3 | 24 DC out | |
| Pull Up Resistor Wiring | ||||
| TB1–16 | 2K ohm resistor Term 1 |
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| TB1–3 | 2K ohm resistor Term 2 |
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Table 2: Promag 400 wired to Rapidlogger Quadrature Input
