Overview of ChemWeb Server
Ext. Reset
If the reset input is connected more than 3 seconds to ground GND or the RESET key is pressed at least 3 seconds, a reset is carried out at the webserver as well as at the modem module.
Terminal No.: | Designation: | Explanation: |
5 | GND | Ground |
6 | Reset | Input for external reset of ChemWeb Server |
Inputs (IN1, IN2)
The two digital inputs are fitted internally with
Terminal No.: | Designation: | Explanation: |
7 | GND | Ground |
8 | IN1 | Digital input 1 – Dialing into internet |
9 | IN2 | Digital input 2 – Switching over to null modem operation |
10 | GND | Ground |
COM 0 - W&T RS485 bus (W&T - RS232)
The serial interface is activated as RS485 port by setting a coding jumper (RS485 enable – GND). At the same time the RS232 interface via DSUB plug is switched off. Without the coding jumper this interface works as standard RS232 via the DSUB connection.
This DSUB connection must not be used in the case of RS485 operation!
Double data lines A and B are connected to the terminals so that the internally existent
If the ChemWeb Server is located at an end position of the RS485 bus, the terminating resistor “Termination” (11) has to be connected to A (15). If the device is coupled in the bus center, “Termination” must remain open.
At least at one point of the bus, the data lines should be connected to B by means of resistor Symm
(+) and to A by means of resistor Symm
Terminal No.: | Designation: | Description: | MG/L 5 | |
Connection | ||||
|
|
| ||
11 | Termination | Bus terminating resistor (at end of RS485 bus) | ||
12 | Symm | Balancing resistor 1 (1 x in RS485 bus) | ||
13 | Symm (+) | Balancing resistor 2 (1 x in RS485 bus) | ||
14 | B | Data line B | ||
15 | A | Data line A | ||
16 | B | Data line B | Terminal 20 | |
17 | A | Data line A | Terminal 21 | |
18 | RS485 enable | Switchover RS485 - RS232 | ||
19 | GND | Ground |
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