Elster EK220, Operating Instructions And Installation Information

Page: 87 / 120

Volume Conversion Device EK220
© Elster GmbH 87
To connect the EK220 to an RS485 bus as a slave, the following settings must be carried
out under the interface list (
®
3.13):
- Md.S2 = 5 No modem control through the EK220, without control signals
- Bd.S2 = 19200 Baud rate 19200 Bd
- TypS2 = RS485 Type of interface RS485
- BusS2 = 1
Bus mode
In addition the bus device address 2:070E of the EK220 must be set to a value
¹
0 with the
aid of the "WinPADS" parameterisation software. The serial number, for example, of the
EK220 as shown on the nameplate can be used as the device address.
4.5 Applications for Interface 2 as RS232
4.5.1 Modem with control signals
F
Connection see Chap. 5.7, page 98
A commercially available modem with RS232 interface is connected to the internal serial
interface of the EK220. For this application the EK220 needs an external power supply.
For the connection of a modem it must be parameterised for automatic call acceptance
and the following settings must be made under the interface list (
®
3.13):
- Md.S2 = 1 No modem control by the EK220, with RS232 control lines,
baud rate selection possible
- Bd.S2 = 19200 19200 Bd - without application of baud rate selection
4.5.2 Modem without control signals
F
For this applications the EK220 needs an external power supply.
F
Connection see Chap. 5.7.2, page 98
The following settings should be made under the interface list (
®
3.13):
- Md.S2 = 3 The EK220 controls the modem by "return messages" via
data lines; without baud rate selection; Num.T is activated.
or = 5 * Without modem control by the EK220, without baud rate se-
lection. Num.T is not activated.
The modem accepts the call automatically.
- Bd.S2 = 19200 * 19200 Bd
- Num.T = ...
Only activated with Md.S2 = 3.
Possible values depend on modem used, e.g.:
- GSM modem Siemens M20T or TC35T ............. 1
- Analogue modem EM200 or Insys Onbit ............ 2 to 9
* Normally, modems do not execute any baud rate selection so that with Md.S2 = "5" the
values under the addresses 02:708 (Bd.S2) and 02:709 must be equal.
For the special case of a modem with baud rate selection, the starting baud rate (e.g. 300
Bd) must be set under the Bd.S2 (address 02:708) and the baud rate identification (e.g.
19200 Bd) under address 02:709.
The ex-works setting is: 02:708 = 19200 Bd and 02:709 = 19200 Bd.