Note: This module will be renamed 1788-FBJB4R
4-way Redundant Intelligent Fieldbus Junction Box
The 1788HP-PARJB protects the integrity of a Foundation Fieldbus H1 or Profibus PA bus by automatically limiting the current to faulty bus segments.
The 1788HP-PARJB provides a simple, redundant and fault tolerant means of connecting a field bus network. The unit comprises a Bus-Input port, Bus-Output and 4 Field Device Drop-Line ports. Each Drop-Line port’s bus current is continuously monitored and if a fault is detected, the current to that specific segment is limited to a safe current. Even with one of the segments shorted, all the other field devices on the bus are able to communicate. Useful field bus diagnostic information is displayed by means of 2 LEDs. The Power LED is illuminated (green) when the unit is receiving power from the PA-Bus.
- OFF - There is no current being drawn. There is nothing on the drop or the device is not operational.
- GREEN - The device on the drop is operating in the allowed current band. For the trunk a solid green LED indicates that the trunk is supplying power.
- RED - The drop is in over-current protection mode. This is because of a faulty field device or a short on the drop. The same applies to the trunk.
- OFF-RED - There is no current being drawn, but the drop was previously in over-current protection. This might indicate a field device that went faulty and then offline or a short that has gone open-circuit (only applicable for drops).
- GREEN-RED - The device on the drop is operating in the allowed current band, but the drop was previously in over-current protection. This might indicate an intermittent fault on the field device or the drop cable (only applicable for drops).
- OFF-GREEN - The (This only applies to the trunk LEDs). When the trunk is receiving power it will flash OFF-GREEN.
Drop Trip If the junction box detects that there is too much current being drawn, it will isolate that drop and keep the rest of the bus operating. The junction box will then indicate which drop is in over-current protection with a constant RED LED indication. Once the short / faulty device is removed the constant red will become OFF-RED. Indicating there was a fault. If the problem has been rectified the user can press the reset button to remove all indication that there was a drop in over-current protection.
Trunk Trip If the trunk goes into over-current it will trip the specific trunk whilst keeping the rest of the redundant bus active. The trip will remove the supply from the over-current trunk and indicate to the user via the RED LED. The fault latch does not unlatch when the fault has been removed. The user will have to reset the trunk trip by either pressing the reset button or setting DIP 3 & 4 to auto-reset.
- Power Requirements
- Power will be connected to the 1788HP-PAJB-6 using the 3 way phoenix connector.
- Operating Voltage: 12 to 32 V
- Power Consumption
- 40 mA at 24 V (max)
- PA Trunk Trip Current
- Operating Temperature
- 0 to 50 ºC
- Storage Temperature
- 0 to 50 ºC
- Enclosure Type Rating
- Profibus PA Conductor
- 18 AWG (0.75 sq.mm) maximum, 24 AWG (0.25 sq.mm) minimum copper wire
- 1788HP-PARJB - 4-way Redundant Intelligent Field Bus Junction Box