Appendix E: ISOLATION AND GROUND

The 3PCIOSD1x provides 2000 VDC minimum isolation on all lines from the DB25 connector to the host computer. The 3PCIOSD1x cards have no connection from pin 1 (chassis ground) to ground of the host computer. This was done to completely isolate the computer end of the communications. In most applications, the shield wire should be connected to ground on only one end of the network. Board space is provided to connect pin 1 to the isolated port ground (pin 7). If you wish to make this connection, it is recommended that a 100Ω ½ watt resistor be installed in R5 of the 3PCIOSD1x. The purpose of the resistor is to limit large currents flowing through the ground connection.

Documentation Number 3PCIOSD1x-3903m Manual

Appendix E

E-1

E-2

Appendix E

Documentation Number 3PCIOSD1x-3903m Manual

B&B Electronics Mfg Co – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104

B&B Electronics Mfg Co – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104

B&B Electronics Ltd – Westlink Comm. Pk. – Oranmore, Galway, Ireland – Ph +353 91-792444 – Fax +353 91-792445

B&B Electronics Ltd – Westlink Comm. Pk. – Oranmore, Galway, Ireland – Ph +353 91-792444 – Fax +353 91-792445

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B&B Electronics manual Appendix E Isolation and Ground, Documentation Number 3PCIOSD1x-3903m Manual Appendix E