Electro Industries Nexus 1262, Installation & Operation Manual

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Electro Industries/GaugeTech Doc # E151701
5-20
5.4: INP2 Internal Modem with Dial-IIn In/Dial-O Out Option
5.4.1: Hardware Overview
Q
The INP2 Option for the Nexus® 1262/1272 meter provides a direct connection to a standard
telephone line. No additional hardware is required to establish a communication connection between
the meter and a remote computer.
Q
The modem operates at up to 56k baud. The internal connection between the modem and the meter
includes a memory buffer. This enables the modem to connect to the phone line at any speed and to
change speed during the communication connection to the remote PC. The buffer between the meter
and the modem allows the meter to communicate into the modem at a constant speed while the
modem telephone line speed can vary. This eliminates the synchronizing problems that are common
with other devices. It also increases the effective throughput of the communication channel. This, in
turn, decreases connection time and connection costs.
Q
The modem supports both incoming calls (from a remote computer) and automatic dial-out calls
when a defined event must be automatically reported.
5.4.2: Hardware Connection
Q
When the INP2 Option is ordered, there are two RJ-11 jacks that pigtail from the back of the
meter (1. Line connection for the outside line 2. Phone connection for your phone). A standard
telephone RJ-11 plug can connect the meter to a standard PSTN (Public Switched Telephone
Network). The phone jack is the override of the modem function when the phone is in use.
With the device configured with the INP2 Option, the meter has dial-in capability and provides
remote access to other Modbus-based serial devices via the meter’s RS485 Gateway over your
phone line. The meter will recognize and respond to a Modbus Address of 1. With any other
address, the command will pass through the gateway and become a virtual connection between the
Remote Modbus Master and any Modbus Slave connected to the RS485 Gateway.
5.4.3: Dial-IIn Function
Q
The modem continuously monitors the telephone line to detect an incoming call. When an incoming
call is detected, the modem will wait a user-set number of rings and answer the call.
Q
The modem can be programmed to check for a password on an incoming call. If the correct
password is not provided the modem will hang up on the incoming call. If several unsuccessful
incoming call attempts are received in a set time period, the modem will lock out future incoming
calls for a user-set number of hours.
Q
When an incoming call is successfully connected, the control of communications is passed to the
calling software program. The modem will respond to computer commands to download data or
other actions authorized by the meter passwords.
Q
Refer to the
Communicator EXT User Manual
for instructions on programming the modem.