Side Access Configuration Panel; Factory Boot" Switch; Figure 10 - Rs485 Connections; Figure 11 - Side Access Panel - Elpro Technologies 915U-2 User Manual

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stop bit which match the 115S serial expansion modules defaults. This port Supports
MODBUS protocol.
The RS-485 port terminal is hosted on the 4 way "Expansion" connector on the bottom
edge of the module. An on-board RS485 termination resistor provides line attenuation
for long runs. As a general rule moreover, a termination resistors should be placed at
each end of the RS485 cable. When using Expansion I/O module remember to switch in
the termination resistor on the end module.
Expansion I/O Power and
RS485 serial connection
115S- XX 115S- XX
915U-2
- - -
+ + +
B B B
A A A
Figure 10 – RS485 Connections

2.5.2 Side Access Configuration Panel

Factory
USB Host Dipswitches
Boot
ON
1 2 3 4 5 6
Figure 11 – Side Access Panel
On the side of the module is a small access cover that hides a "Factory Boot" switch,
USB Host port and a small bank of dipswitches that are used for Analog input
voltage/current selection, External Boot and Default configuration settings.

"Factory Boot" switch

The "Factory Boot" switch is used for factory setup and diagnostics. This switch should
not normally be used, except if advised by ELPRO support.
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