Pressure - What is Hardware Write Protect?

Hardware Protection

Transmitters used in safety systems, environmentally sensitive applications, custody transfer, or critical processes need to be secure from tampering or inadvertent changes to their setup that may lead to errors and failures. Yokogawa’s pressure transmitters have the security of a Software Write Protection (Password) and a Hardware Write Protection (Switch) to secure programming changes and physical cover locks to secure the transmitter electronics. These security features can be applied independently or in combination to build the level of security desired.

Write Protect

The hardware write protection is a physical slide-switch located within the transmitter. To reach the switch, the transmitter must have power removed, have the amplifier cover removed, as well as the display board (if equipped). The Write (WR) switch is located on the CPU Assembly Board with the Burn Out (BO) switch. When the WR switch is in the "D" (Disabled) position, the transmitter disables parameter changes through the use of a handheld communicator (HHC), FieldMate, or Local Parameter Setting (LPS) function on the transmitter display (if equipped). When the WR switch is in the "E" (Enable) position, parameter changes are allowed.

Shrouding Bolts

On ATEX Flameproof Type transmitters, the two covers, amplifier cover and terminal block cover, are locked using Allen head bolts. When locked, the covers cannot be removed without causing damage to the covers. The bolts must be engaged to allow the removing of the covers.

Not required for other types of approvals, the shrouding bolts can be added to increase the tamper resistance of the transmitter.

See the attached FieldGuide FGP-110 Transmitter Security for more detail.