SPA Bus Connection Modules Product Guide S

SPA Bus Connection Modules

Features 

• Electrical-to-optical converter for the SPA bus 

• Connects the substation secondary devices to the fibre-optic SPA bus 

• High immunity to electrical and electromagnetic interference 

• Easy mounting and installation 

• Complete range of bus connection modules for different applications 

• Products of the SPACOM product family and ABB’s Substation Automation system

Application

The SPA bus interconnects the substation protection relays, annunciator systems and other devices by means of a fibre-optic loop based on a glass or plastic fibre cable. The devices are connected to the bus over bus connection modules type SPA-ZC_ which convert the electrical signals of the devices to optical signals for the bus and, vice versa, the optical signals of the bus to electrical signals of the devices. All the standard secondary devices of a substation are equipped with a serial interface for receiving and transmitting information. The serial ports of the devices are TTL, RS 485 or RS 232 C signal level interfaces. Bus connection modules are available for these interface types

Design

The SPA bus connection modules are used in both ends of the SPA bus, i.e. on the substation level for connection of the bus to the communication units and on the feeder level for connection of the bus to the substation secondary devices.

Bus connection module SPA-ZC 17

The bus connection module SPA-ZC 17 is used for connecting substation secondary devices to the SPA bus. It converts the TTL or RS 485 level signals of the host device to fibre optic signals for the bus and vice versa. The unit comprises one 9-pin D type connector for the host device and one pair of optical transceivers for the SPA bus. The module can be powered from the host device or from a separate power source. In the latter case the bus connection module and the fibre-optic bus remain operative, should the power supply from the host device be interrupted. The bus connection module SPA-ZC 17 can be used in both master and slave mode.

Bus connection module SPA-ZC 20

The bus connection module SPA-ZC 20 is used for multiplying the number of available fibre-optic loops in a substation. The module is provided with 15 transceiver pairs, that is it can form 15 fibre-optic loops. All of the loops formed by the module carry the same information. In certain applications, where operational reliability is of primary concern it can

be recommended to limit the number of substation secondary devices connected to one single loop. In these applications the bus connection module SPA-ZC 20 is applied. The SPA-ZC 20 is only used in master mode and it is powered from the device to which it is connected. The input interface of the device is of the RS 485 type.

Bus connection module SPA-ZC 21

The bus connection module SPA-ZC 21 is used for connecting substation secondary devices to the SPA bus. It converts the TTL or RS 485 level signals of the host device to fibre optic signals for the bus and vice versa. The unit comprises one 9-pin D type connec

tor for the host device and one pair of optical transceivers for the SPA bus. The module is powered from the host device. The bus connection module SPA-ZC 21 can be used in both master and slave mode.

Bus connection module SPA-ZC 22

The bus connection module SPA-ZC 22 is used for dividing the system into several fibre-optic loops. The SPA-ZC 22 module is available in two versions, one with five fibreoptic transceiver pairs and one with two pairs. The SPA-ZC 22 module is connected to the communicator units of the SPA loop. The bus connection module features a built in RS 232 C interface for direct connection to a PC, a modem, etc. and one RS 485 interface for connection to e.g. a SRIO unit. The bus connection module can also be used in slave

mode if a double connection to one substation secondary device is needed. The third mode of operation for the SPA-ZC 22 module is the optical repeater mode. In the optical repeater mode a fibre pair from the communicator unit's optical module is connected to the first transceiver pair of the SPA-ZC 22 module. The data is then retransmitted over the other transceiver pair(s) in the module. The bus connection module SPA-ZC 22 is powered form the device to which it is connected or from an external power source.