Module Status Leds; Daisy Chaining Multiple Usb-Ssr08 Devices - Measurement Computing USB-SSR08 User Manual

USB-SSR08 User's Guide
Caution! Before connecting wires to the screw terminals, turn off the power to the USB-SSR08, and make
sure that the signal wires do not contain live voltages.
Use 12-22 AWG wire for your signal connections. Properly insulate the wires to avoid any short circuit to the
other channels, ground, or other points on the device.
Caution! Keep the length of stripped wire at a minimum to avoid a short to the enclosure! When connecting
your field wiring to the screw terminals, use the strip gage on the terminal strip, or strip to 5.5 to
7.0 mm (0.215" to 0.275") long.
Pin
1+
1-
2+
2-
3+
3-
4+
4-

Module status LEDs

Independent red LEDs next to each module screw terminal pair indicate the on/off status of each module. The
LED turns on when an output module is active or when an input module detects an input voltage (logic high).

Daisy chaining multiple USB-SSR08 devices

Daisy chained MCC USB Series devices connect to the USB bus through the high-speed hub on the
USB-SSR08. You can daisy chain a maximum of four MCC USB Series devices to a single USB 2.0 port or
USB 1.1 port on your computer. Use the supplied cable or an equivalent cable when daisy chaining MCC USB
Series devices.
To daisy chain two or more USB-SSR08 devices, follow the steps below. This procedure assumes you already
have one USB-SSR08 connected to a computer and to an external power source. The USB-SSR08 already
connected to the computer is referred to as the connected device. The USB-SSR08 you want to daisy chain to
the connected device is referred to as the new device.
1. Connect the
Power OUT
This step is required only if you plan to daisy chain power to another device.
2. Connect the
USB OUT
3. To add another device, repeat steps 1-2, with the device you just connected now being the connected
device.
Figure 10. Screw terminals
Signal Name
Module 1+
Module 1-
Module 2+
Module 2-
Module 3+
Module 3-
Module 4+
Module 4-
connector on the connected device to the
connector on the connected device to the
14
Pin
5+
5-
6+
6-
7+
7-
8+
8-
connector on the new device.
Power IN
connector on the new device
USB IN
Functional Details
Signal Name
Module 5+
Module 5-
Module 6+
Module 6-
Module 7+
Module 7-
Module 8+
Module 8-