GEM80
6. Maintenance and Fault Finding
Issue 002 (07/05)
Fieldbus Technical Manual T2035
Page 14
All device controlled or uncontrolled settings should be avoided as the Fieldbus
communication will start as soon as power is applied, without waiting for the Ethernet
module (9716-4020) to initialise. The Fieldbus slaves will therefore not be under the
control of the GEM80.
6.1.3
Exchange Counter
This unsigned 32-bit variable contains the count of transfers between the GEM80 and
the Fieldbus module.
6.1.4
Presence Indication
The Fieldbus module maintains a bit array of the active devices detected on the
communications link. It is recommended that the application monitors this bit array and
takes appropriate action on loss of I/O. Word 0 bit 0 represents the master itself and
will always contain 0. Word 0 Bit 1represents the device with address 1 etc.
Presence Words 4 to 7 are not required when using DeviceNET and should be ignored.
Module 1 Module 2 Description
F378
F392
Presence Word 0 (Addresses 0 to 15)
F379
F393
Presence Word 1 (Addresses 16 to 31)
F380
F394
Presence Word 2 (Addresses 32 to 47)
F381
F395
Presence Word 3 (Addresses 48 to 63)
F382
F396
Presence Word 4 (Addresses 64 to 79)
F383
F397
Presence Word 5 (Addresses 80 to 95)
F384
F398
Presence Word 6 (Addresses 96 to 111)
F385
F399
Presence Word 7 (Addresses 112 to 127)
