ABB-SPA-ZC-Bus Connection Modules

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 connector 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.