User guide

Modbus/BSAP Configuration
Rev 2.3 Feb.12 171
Configuring the AirLink Device at the Polling
Host for Modbus on UDP
This section covers a Polling Host with standard Modbus. Variations may need
additional AT commands.
1. Configure the ports.
The destination port for the modem at the host needs to match the device port
(*DPORT) in use on all the modems at the remote sites. For example, if the
remote modem’s device port (*DPORT) is “12345”, then the Modbus host
modem's S53 destination port should be set to “12345”.
Take note of (or set) the Device Port setting in *DPORT to configure the
destination port on the remote modems.
In ACEmanager, select UDP in the side menu. Select the appropriate MD mode
from the drop down menu:
•MD13: Modbus ASCII
•MD23: Modbus RTU (Binary)
•MD33: BSAP
•MD63: Variable Modbus - individual parameters are set up manually.
If you do not have a static IP, the host modem should be configured to report its
current IP to a Dynamic DNS (DDNS) server with Dynamic DNS.
In the Host modem’s configuration, instead of IP address for the Addr List
(ATMLIST or ATMLISTX), substitute a single unique name for each modem, i.e.,
remote1, remote2, etc.
When you configure Dynamic DNS for the host modem, make note of your
modem name and domain setting in ACEmanager in the menu selection Dynamic
IP to be used with the remote modems.
With names instead of IP addresses for the Address List, the host modem will
query the DNS server for the current IP address assigned to the specific name of
a remote modem to send a message corresponding to the ID.
When you use names instead of IP addresses, to ensure your modems are
updated quickly with the correct IP addresses for the names, you will want to set
the DNS settings as well. In ACEmanager, select DNS.
Configure *DNSUSER to the same IP address as the Dynamic DNS
(*IPMANAGER1). If your modems have dynamic IP addresses and not static (the
IP address can change when it is powered up), configure *DNSUPDATE to a low
interval to allow frequent updates.