The Problem/ Study Case :
A customer had some remotely located equipment controlled by a PLC and supervised by an operator who visited the site routinely. Following extensive investigations regarding the performance of the plant, it was concluded that routine visits were not required to ensure efficient operation of the plant. What was required was some method of reporting alarms and a method of communicating with the PLC remotely.

The Solution: Without a network connection or telephone line at the plant is was decided that the best solution was to use a Robustel Gorugged M1000 Smart GPRS Modem to enable remote wireless communication with the PLC, and the SMS provided the easiest method of communication with a PLC. By using Robustel proprietary SMS Direct whatever ASCII string is sent to the modem it simply transmits this message as an SMS text message via the GSM network to a predefined mobile phone number. Conversely SMS messages sent to the modem from a mobile phone are forwarded to the PLC.

The Result: Following successful field trials this solution has now been applied to multiple sites. Whilst previously the equipment was virtually manned full-time it has now been possible to operate the equipment unmanned with on-site visits only required when an alarm condition has to be attended to.
1. Receive updated operating status information by verifying integrated information
and power status.
2. Detect machine malfunctions, notify related personnel and control center for
immediate response.
3. Eliminate unnecessary machine downtime, ensure maximum productivity.

Robustel proprietary SMS Direct has the following features:
1. Transparently converts serial data to short message or vise versa without
using AT Commands.
2. Text, binary, and Unicode formats are supported.
3. Verification of Incoming Caller ID is implemented to block uncertified users.
4. The configuration profile can be easily stored, and then copied to other modems.

Possible Applications:
Update the message on a highway LED signage display panel
Place refill orders for vending machines
Handle maintenance for remote rental equipment
Create SMS alarm for legacy device

M1000 Overview:
1. Rugged design with highly EMC performance
2. Din-Rail mounting installation
3. 3 level RSSI LED indicators
4. Wide range power supply range from 9 to 36VDC
5. Wide range temperature range from -25 to 70oC
6. Auto reboot at preset time of a day, via phone call, via SMS, to keep modem 24x7 running
7. Read modem status via SMS
8. SMS Direct function

Specifications
1. Quad Band GSM 850/ 900/ 1800/ 1900 MHz
2. GPRS multi slot class 10
3. CSD data transmission rate up to 14.4 kbps
4. RS232 & RS485 selectable by software, built in 15KV ESD protection
5. SIM Card reader: 3V, 1.8V
6. 6 LED indicators: 3 level RSSI, PWR, RUN, NET
7. Built in real time clock with button battery
8. Builtin watchdog and timer
9. Power supply interface: 2 pin 5mm pluggable terminal blocks
10. Input voltage: 9 to 36 VDC
11.Operating temperature: -25 to 70° C
12.Installation: 35mm Din Rail or wall mounting or desktop

Features
1. Configuration modeand Normal modeselecting by switch
2. GPRS, built in PPP and TCP/ IP stack
3. CSD
4. Control via AT commands ( Hayes 3GPP TS 27.007 and 27.005)
5. Send / receive SMS via AT commands ( Under normal mode)
6. SMS DirectMode can transparently converts serial data ( Text) to SMS or vise versa without using AT Commands, verification of incoming Caller ID is implemented to block uncertified users. ( Under Configuration Mode)
7. Auto Reboot
Auto reboot at preset time of a day
Auto reboot via telephone call
Auto reboot via SMS
8. Read modem status via SMS
9. Firmware upgrade via serial interface