Setup
Connection Specifications
maxon motor control
EPOS4 Positioning Controller
Document ID: rel8003
3-63
EPOS4 Module/Compact 50/5 Hardware Reference
Edition: May 2018
© 2018 maxon motor. Subject to change without prior notice.
3.4.10 Serial Communication Interface (SCI) / RS232
The SCI is a two-wire asynchronous serial port, commonly known as a UART. The SCI modules support
digital communication between the CPU and other asynchronous peripherals that use the standard non-
return-to-zero (NRZ) format.
A common use of the Module’s SCI is to build an RS232 interface by wiring it to an RS232 transceiver.
Alternatively, using any of the Compact versions does not require an external transceiver.
Bit rate settings
• Consider the master’s maximal bite rate.
• The standard bit rate setting (factory setting) is 115’200 bit/s.
3.4.10.1
Module
Table 3-56
SCI – Pin assignment
Module
Header Pin
Signal
Description
B38
GND
Ground
B39
*6)
DSP_RxD
Serial communication interface receive (UART)
B40
DSP_TxD
Serial communication interface transmit (UART)
6)
connect to sensor supply voltage V
Sensor
(A40) when RS232 is not in use
Serial Communication Interface (SCI)
Input voltage
0…3.3 VDC
Max. input voltage
5 VDC
High-level input voltage
>2.0 VDC
Low-level input voltage
<0.8 VDC
High-level output voltage
>2.4 VDC
Low-level output voltage
<0.4 VDC
Max. bit rate
115’200 bit/s
Data format
NRZ (non-return-to-zero)