Landis+Gyr CU-B1 - User Manual

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Overview

Function Description
Application of Interfaces
Important Technical Specifications
Usage Features
Maintenance Features

The Landis+Gyr E65C CU-Bx is a communication unit designed to supplement ZxDxxxAT/CT meters, providing various interfaces for remote meter scanning and external signal transmission. It is a self-contained unit housed in its own plastic case, allowing for easy installation and removal from meters without breaking calibration seals. The unit connects to the meter electronics via plug contacts at the rear and offers external connections through spring-loaded terminals at the bottom.

Function Description:

The CU-Bx communication unit is controlled by a microprocessor that communicates with the meter's microprocessor, managing its various interfaces: S0, RS485, and RS232.

Pulse Inputs (S0 Interfaces): The CU-Bx can receive pulses from external pulse generators via its S0 inputs (terminals 20-21 for S01, 22-23 for S02). These pulses are recorded in the total energy register and, in versions with demand recording, in a P running register. If the meter has a data profile memory, it can also record the energy status and/or the mean value of demand P running of the external meters in the data profile. The pulse generators must comply with IEC 61393 or DIN 43864 standards.
RS485 Interface: This serial, bi-directional interface is standardized to ISO-8482 and operates on a difference signal principle, allowing multiple drivers to connect to the transmission path. Up to 32 transceivers can be connected to one line, enabling bus or local semi-duplex "multipoint" network operations. This interface is suitable for simple remote reading, such as connecting several meters in a bus system to a central modem for readouts and parameterization. Depending on the version, it supports communication protocols according to IEC 61107 or both IEC 61107 and DLMS.
RS232 Interface: This asymmetric, serial, asynchronous, bi-directional interface complies with DIN 66259. It allows for the operation of an external modem for data transfer with a central system or a direct connection to a computer. In its "transparent" version, the interface handles communication and requires an intelligent external modem. Versions with additional functions can control and monitor an external modem and operate with time-windows, making them dependent on a transparent external modem.

Application of Interfaces:

Single Application (CU-B1/B4): The meter is permanently connected to the telephone network via its RS232 interface, with a modem connected for remote reading (ISDN/PSTN/GSM/METCOM, etc.).
Multiple Application (CU-B1/B4 as Master with CU-B2 as Slaves): This setup allows connecting several (up to 31) ZxDxxxAT/CT meters. One meter with a CU-B1 or CU-B4 acts as the master, and other meters with CU-B2 units act as slaves. The RS485 interface terminals are internally looped, connecting meters in a chain. Communication with all meters occurs via the master's RS232 interface, which can be connected to a PC/laptop for temporary service functions or re-parameterization, or to a communication network via a modem.
Multiple Application (Several CU-B1/B4): Similar to the previous multiple application, but all communication units are CU-B1/B4, meaning each unit has a free RS232 interface for temporary service functions or fixed communication.

Important Technical Specifications:

Weight and Dimensions: Approximately 80 g, 65 mm width, 103 mm height, 38 mm depth.
Pulse Inputs (S0 Interface):
- Type: S0 interface (Version CU-B1 only)
- Standard: IEC 61393 / DIN 43864
- Rated voltage: 24 V DC
- Max. voltage: 27 V DC
- Condition "On" current: min. 10, max. 27 mA
- Condition "Off" current: max. 2 mA
- Pulse length: ≥ 30 ms
- Max conductor length: up to 0.5 m (depending on environment and connecting cable)
- Insulation resistance to meter: 4 kVAC / 50 Hz, 1 min (creep distance min. 6.2 mm)
RS485 Interface:
- Type: Symmetric, serial, asynchronous, bi-directional
- Application: Versions CU-B1, CU-B2, CU-B4
- Standard: ISO-8482
- Signal condition binary 1: difference voltage < -0.2 V DC
- Signal condition binary 0: difference voltage > 0.2 V DC
- Max. bit rate: 38'400 bps
- Max. number of slaves: 31
- Max conductor length: up to 300 m (depending on environment and connecting cable)
- Insulation resistance to meter: 4 kVAC / 50 Hz, 1 min (creep distance min. 6.2 mm)
RS232 Interface:
- Type: Asymmetric, serial, asynchronous, bi-directional
- Application: Versions CU-B1, CU-B4
- Standard: DIN 66259
- Rated voltage: +12 V DC
- Max. voltage: ±25 V DC
- Max. bit rate: 57'600 bps
- Max conductor length: up to 15 m (depending on environment and connecting cable)
- Insulation resistance to meter: 4 kVAC / 50 Hz, 1 min (creep distance min. 6.2 mm)
Connections:
- Pulse inputs (S0 interface): Screwless spring-loaded terminals
- Communication interfaces (RS232 and RS485): RJ12 plug
- Connections to meter: 10-pin and 4-pin p.c.b. connector

Usage Features:

Time-Window for Communication (RS232): This feature determines when the meter can communicate with the control centre for remote reading.
- No readiness: External modem is out of service.
- Reception at all times, daily, weekly or monthly: The modem accepts incoming calls from the control centre for remote reading within defined time-windows or after a parameterised number of ringing tones outside the window.
- Emergency window: Can be activated with weekly or monthly communication windows. The modem opens this emergency window 24 hours after the regular communication window if no remote reading occurred within the regular time-window.
LED Functions:
- CON (Connection): For CU-B1 and CU-B4 (with RS232), this LED is continuously lit when a connection exists between the communication unit and the control centre, indicating data exchange can take place. No function in CU-B2.
- Rx (Receive): Indicates reception of characters via the RS232 or RS485 interface, extended by 100 ms. Flashing indicates reception of the "Ring" function.
- Tx (Transmit): Indicates transmission of characters via the RS232 or RS485 interface, extended by 100 ms.

Maintenance Features:

Installation and Removal: The CU-Bx unit can be fitted and removed from meters without opening the calibration seal. Installation requires ensuring no voltage is applied to the meter, removing company seals, opening the front door, removing the terminal cover, and replacing any "dummy" communication unit. The unit is then carefully inserted, and the front door is closed and sealed.
Connecting Signal Inputs: Connecting wires for S0 inputs should be shortened, stripped for approx. 4 mm, and inserted into the screwless spring-loaded terminals using a size 1 screwdriver. Stranded wires should ideally be fitted with ferrules. Proper insulation length is crucial to prevent contact with live parts. Disconnecting wires is done in reverse sequence.
Connecting Communication Interfaces: RJ12 connectors for RS232 (left) and RS485 (right) are inserted until they engage.
RS485 Wiring: For correct RS485 function, all three wires (data a, data b, and Common GND) must be connected. Two-wire operation (without Common GND) is forbidden as it may cause incorrect function or damage.
Commissioning and Functional Check:
1. Connect a signal source to the S0 interface and verify register changes if the meter is configured to process the signal.
2. Perform a data readout via the RS485 or RS232 interface using a suitable unit (laptop, handheld terminal).
3. Ensure all units connected to the RS485 interface have different IEC unit addresses (for IEC 61107) or physical unit addresses (for DLMS).
4. Verify that all units connected to the RS485 interface use the same bit rate.
- Safety Note: Preliminary fuses must be re-inserted for commissioning. Contact with live parts is dangerous; ensure terminal cover is screwed on.
Troubleshooting and Repair:
- Removal: Before removing the CU-Bx, ensure the meter and connecting conductors are voltage-free by checking with a phase tester or universal measuring set, and removing corresponding fuses. Remove company seals, terminal cover, and open the front door. The unit is then removed by pulling on the flap at the left top side.
- Repair: Communication units CU-Bx should only be repaired by the responsible service and repair centre. If repair is needed, remove the unit, fit a replacement if available, accurately describe the error, pack the unit securely (preferably in original packing), and send it to the service centre.
- Safety Note: The meter must not be operated without a communication unit or a "dummy" communication unit for safety reasons.
Decommissioning and Disposal: The product must not be disposed of in regular waste. It requires professional electronic waste treatment. Components can be broken down for recycling: printed circuit boards to recycling plants, metal components to metal recycling plants, and plastic components to re-granulation if possible. All processes must comply with local regulations.