tM-SG4 CR
RS-485 pull-high/pull-low and termination resistors module
- Switch-selectable Pull-high/Pull-low Resistors
- 15-step Switch-selectable Termination Resistor
- LED Indicator for Power/Termination
- DIN-Rail mountable
- Cost-effective
- Wide Operating Temperature Range: -25 °C ~ +75 °C
INTRODUCTION
The tM-SG4 is an optional module that is used to improve the communication of RS-485 network. It provides switch selectable pull-high and pull-low resistors on RS-485 network. It also has 15-step switch selectable termination resistor such that the user can select a proper termination resistor to be connected to the RS-485 network easily. If the RS-485 network is not over 100 meters, the termination resistors are not needed. Otherwise, it may be necessary to insert two termination resistors at both end of the RS-485 network. It is not easy to calculate the value of a termination resistor on the RS-485 network. The best way to do this is to use an oscilloscope to check the RS-485 signal directly. If the impedance match of RS-485 network is OK, the oscilloscope will show a very nice square wave. If these square wave signals are distorted, the user will need to insert two termination resistors at both end of the RS-485 network.
SPECIFICATIONS
RS-485 Interface
Pull-high/Pull-low Resistance: 1 kΩ, 10 kΩ, 100 kΩ, Switch-selectable
Termination Resistance: 15 Steps, 65 ~ 560 Ω
LED Indicators
Power: 1 Red LED as Power Indicator
Termination Resistor: 1 Green LED as Termination Indicator
EMS Protection
ESD (IEC 61000-4-2): ±4 kV Contact for Each Terminal
Power Requirements
Reverse Polarity Protection: Yes
Powered from Terminal Block: Yes, 10 ~ 30 VDC
Consumption: 0.5 W Max.
Mechanical
Dimensions (W x L x H): 52 mm x 87 mm x 27 mm
Installation: DIN-Rail Mounting
Environment
Operating Temperature: -25 ~ +75 °C
Storage Temperature: -40 ~ +85 °C
Humidity: 10 ~ 90% RH, Non-condensing