GE B90 Instruction Manual page 312

11.1 MODULES
To properly insert a module, ensure that the correct module type is inserted into the correct slot position. The ejector/
inserter clips located at the top and at the bottom of each module must be in the disengaged position as the module is
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smoothly inserted into the slot. Once the clips have cleared the raised edge of the chassis, engage the clips simultaneously.
When the clips have locked into position, the module will be fully inserted.
CPU connections must be individually disconnected from the module before the module can be removed from the
chassis.
NOTE NOTE
The 4.0x release of the B90 relay includes new hardware modules.The new CPU modules are specified with codes
9E and higher. The new CT/VT modules are specified with the codes 8F and higher.
NOTE
The new CT/VT modules can only be used with new CPUs; similarly, old CT/VT modules can only be used with old
CPUs. In the event that there is a mismatch between the CPU and CT/VT module, the relay will not function and a
DSP ERROR
All other input and output modules are compatible with the new hardware. Firmware versions 4.0x and higher are
only compatible with the new hardware modules. Previous versions of the firmware (3.4x and earlier) are only com-
patible with the older hardware modules.
11-2
or error will be displayed.
HARDWARE MISMATCH
B90 Low Impedance Bus Differential System
11 MAINTENANCE
GE Multilin