Clear-Com 4000 series II, Technical Manual, Page: 117 / 134

4000 Digital Series
II
Issue 2.1 Technical Manual
STA0381 Page 93
The SCRCU requires two EPROM devices. Before fitting this card ensure that the EPROMS are
present and verify that the version of firmware is correct for the application.
Figure 82 - PDE 4628 - 16 Channel Serial Communications RCU
4.8.5.1 Card Location
These cards may be located in any RCU slot from 3 to 20 in the 4920 matrix, or any RCU slot from 2 to
7 in the 4420 matrix. However, these RCUs must be fitted in a RCU slot directly behind a PDE 4621
CODEC Card.
4.8.5.2 Upgrading Firmware
If firmware needs to be upgraded then U29 and U30 should be replaced.
4.8.5.3 Power On Self Test
On power up, the SCRCU will conduct a series of power on self-tests. While this is taking place, the
SCRCUs matrix of 35 LEDs will indicate the current test, as indicated by the following characters:
Table 12: PDE 4628 Self Tests
Action LED Display Indication
Display Test Appears for 1 second