MAN0964-14-EN_XL4_XL4P_UM
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10.6 RS-485 Biasing
RS-485 biasing passively asserts a line-idle state when no device is actively transmitting, which
is useful for multi-drop RS-485 networking.
The 485 serial ports allow internal RS-485 bias resistors to be switched in, pulling pin 1 up to
3.3V and pulling pin 2 down to ground. The Set Serial Ports item in the System Menu can be
used to enable RS-485 biasing. Also, an application graphics screen that writes to %SR164 can
do the same thing. Setting %SR164.1 enables MJ1 biasing and setting %SR164.2 enables MJ2
biasing.
If biasing is used, it should be enabled in only one of the devices attached to the RS-485
network.
10.7 Cscape Programming via Serial Port
The XL4/XL4 Prime OCS MJ1 serial port supports CsCAN Programming Protocol. If a PC COM
port is connected to the XL4/XL4 Prime OCS MJ1 serial port, Cscape can access the XL4/XL4
Prime OCS for programming and monitoring. Programming can also be done via the CAN port,
USB port or Ethernet. Successful communications with USB-to-serial adapters vary. If in doubt,
Horner APG offers a USB to serial adapter. Part numbers HE-XCK and HE-CPK.
10.8 Ladder-Controlled Serial Communication
Using Serial Communication function blocks, both MJ1 and MJ2 support Generic, Modbus
Master, and Modbus Slave Protocols. In addition, external modems can be connected and
accessed using Init and Dial and Answer Modem function blocks.
10.9 Configuration via Mini-B USB
NOTE: The unit must be connected via the mini-USB port to the PC or laptop.
It is possible to load the program and monitor data via the Mini-B USB. To load via Mini-B USB,
configure the communications port in Cscape as follows:
Select Tools from the toolbar
→
Application Settings
→
Communications
→
USB button
It is possible to download or upload and use the data monitoring functions once connected.
NOTE: It is advisable to use an isolated USB cable between the PC or laptop and the XL4/XL4
Prime when third party devices are connected to the XL4/XL4 Prime to avoid damage to the
PC or laptop and/or the XL4/XL4 Prime.