Siemens Cerberus GW-21, Technical Manual, Page: 7 / 44

3
Siemens Building Technologies
Cerberus Division
E1481b
06.2000
2 Product Description
2.1 CPU board
The CPU board is the main board. It must be present in any gateway GW-21, aside
from its configuration.
Neuron
Chip
Flash EPROM
RAM
CPU
RTC
UART
UART
Reset
Service
UART1
UART2
UART3
UART4
R X
TX
R X
TX
R X
TX
R X
TX
service pin LED
Diagnostic
S3
S4
S2
S1
1 2 8 7 6 4 3 5
8
7
6
4
3
2
1
5
8
7
6
4
3
2
1
5
2 8 7 6 4 3 5 NC
Fig. 1 The CPU board
On this board there are:
§
the CPU, the RAM and Flash EPROM
§
the Real Time Clock (RTC)
§
two UART chips, that manage the four GW-21 serial lines
§
the Neuron Chip, that lets the GW-21 to communicate with the LonWork network
§
four DIL switch blocks (S1 - S4), used to configure the GW-21 as described later
§
one reset push-button, used to reset the board
§
one service push-button, to send the service signal to the Neuron Chip
§
four sets of two LEDs. These LEDs show the status of UART RX/TX lines.
§
three LEDs used for diagnostic purposes.
For GW-21, the CD95800 board is configured as type 3 (check label on the RTC com-
ponent).
The three diagnostic LEDs marked LD1, LD2 and LD3 have the following meaning:
ON OFF Blinking
LD1
(green
) Firmware vitality failure or
out of memory jump Firmware vitality failure or
out of memory jump Firmware vitality OK
LD2
(red)
Download failed OK Slow (1Hz): RAM test failed
Fast (4Hz): wrong configuration
or download in progress
LD3
(yellow)
- - -
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