TS-7250-V3 TS-ISO485

From Technologic Systems Manuals
TS-ISO485
TS-ISO485.jpg
Product Page
8-bit IO

The TS-ISO485 provides two isolated half duplex RS-485 ports, or two isolated RS-422 ports.

Refer to the TS-ISO485 manual for more information about the hardware UART usage.

The TS-ISO485 implements 16550A based UARTs which require a kernel driver. Under Linux this requires a device tree change. See the Kernel compile section for more details about getting set up the compile the kernel.

This below example will set up the serial devices for a TS-ISO485 with the IRQ2,IRQ4, and SHARE jumpers installed. Open the device tree at arch/arm/boot/dts/imx6ul-ts7250v3.dts. Add the highlighted section to the device tree and recompile.

pc104bus: fpgaisa@50 {
	compatible = "technologic,pc104-bus";
	reg = <0x50 0x4>;

	ranges = <0 0 0x1000>;
	reset-gpio = <&gpio3 7 0>;

	#address-cells = <0x1>;
	#size-cells = <0x1>;

	status = "okay";

	/* TS-ISO485 COMA */
	ts16550@3e8 {
		compatible = "technologic,ts16550";

		reg = <0x3e8 8>;
		interrupt-parent = <&fpga_intc>;
		interrupts = <15>;

		status = "okay";
	};

	/* TS-ISO485 COMB */
	ts16550@2e8 {
		compatible = "technologic,ts16550";

		reg = <0x2e8 8>;
		interrupt-parent = <&fpga_intc>;
		interrupts = <15>;

		status = "okay";
	};
};

On the next boot check the "dmesg" output to verify it loaded:

root@tsimx6:~# dmesg | grep ts16550
[    2.259413] ts16550 50004050.fpgaisa:ts16550@3e8: Adding 16550 UART ttyS0
[    2.268166] ts16550 50004050.fpgaisa:ts16550@2e8: Adding 16550 UART ttyS1

Now that these are loaded:

Device Description
/dev/ttyS0 COMA
/dev/ttyS1 COMB

In this mode COMA/COMB are full duplex RS-485 (RS-422). See the TS-ISO485 manual for mroe details on the HD jumpers to use half duplex.