Michael

I have a similiar issue. I am running Windows Vista. I see the same access denied message when opening the communication settings dialog. Notice this is not happening when I try to communicate, but it shows up when I open the communication settings dialog box. See attached screen shot. I'm not sure if this is related to my communication problem or not. I can ping the V230 PLC with no problem. When I try to connect via telnet to troubleshoot the tcp connection on port 20256, it does not connect. If I connect the V230 PLC to a different computer runing Windows XP and similiar IP settings then I don't have any problems. I can execute the "telnet 147.167.140.110 20256" command with no problems and remote operator works fine. Why does the Windows Vista computer have this problem?

I am posting this update for anyone else that may need it. Firmware and documenation for the Enfora modem is at: http://www.enfora.com click on support then select documenation. in the drop down box select SA-G+

I have a V230 with enfora modem and I have a PC with another enfora modem. I would like the ability to call the PLC from my PC so that I can do remote program changes. I can get the PLC to call my PC, but this connection is very poor with constant retries and its not good enough to download a new program. I am using AT&T prepaid SIM cards. When you register to use the GPRS network, you are issued a dynamic IP. The reason I am not using static IPs is because AT&T does not offer it with prepaid accounts. I know it is recommended to get a static IP in order to allow the PC to call the PLC, but I have read online that if you have version 1.4 of the enfora firmware, you can setup a PPP (dial up) network on the PC side. Then you will have a dynamic IP on the PLC and a dynamic IP on the PC that are on the same subnet and I am told by AT&T that this will allow the PC to call the PLC. My problem is that Enfora will not respond to my request for the firmware upgrade, but I know it exists because I can find the pdf online that tells how to install the firmware and also the pdf that describes how to setup the PPP (dial up) network provided you have upgraded the firmware to 1.4. Can someone help me get the updated firmware?

I need to add a static address to my router to allow this PLC to send emails. I need to determine the MAC address to be able to do this. I have tried the MAC address to ASCII FB, but it just returns 0. I have no problem going online via Ethernet with the PLC so I know the Ethernet works fine. I have also physically looked on the Ethernet option card, but I do not see the MAC address there either.

I did some research and found out why I'm having problems. I am writing this for everyone else to benefit and not make the same mistake I made. AT&T prepaid currently uses GPRS for data they do not support CSD (although special business accounts can be setup to use CSD for the right price). CSD is required to dial another GSM modem for data access. Instead you must use GPRS. See below for an explaination of the different data types available. GSM Data Overview GSM divides each radio channel into 8 time slots. Data speeds are determined by the speed of an individual time slot, and the number of time slots used:CSD (Circuit Switched Data)9.6 Kbps over a single time slot. Most GSM phones support CSD. (2G) AT&T prepaid does not support this.HSCSD (High Speed Circuit Switched Data)Each time slot can be 9.6 or 14.4 Kbps, and multiple time slots can be combined for higher speeds, up to 38.4 and 57.6 Kbps respectively. Much less efficient than GPRS from a network standpoint, a significant drawback. (2.5G)GPRS (General Packet Radio Service)Each time slot can be 9.6 to 21.4 Kbps, and multiple time slots can be combined for higher data speeds, up to 171.2 Kbps (all 8 time slots), although current phones are limited to lower data speeds. In practice, GPRS data connections are usually limited to a maximum of 4 downstream time slots with 1 upstream time slot. Packet technology greatly enhances network efficiency. (2.5G)EDGE (Enhanced Data GSM Environment)Effectively an extension of GPRS that increases maximum time slot speed to 48 Kbps, pushing maximum combined data speed up to 384 Kbps (all 8 time slots). In trials, but not yet widely deployed. (3G)In each case, actual availability and speed is determined by the lowest common denominator of: what the carrier offers; how the subscriber is configured by the carrier; configuration of the actual access point in use; and the capabilities of the phone in use. It's a common misconception that GSM phones can make analog (dial-up) modem calls directly, but they can't. GSM is digital, and analog modems will only work over analog (AMPS) cellular. The "modem" in a GSM phone actually makes a digital connection to an IWU (Inter Working Unit) located at a carrier's Mobile Switching Center (MSC). The IWU has an analog modem bank that makes the actual dial-up modem calls. If a carrier doesn't provide an IWU, then analog modem calls are not possible.

Thanks for your help. Can I use GPRS to go online with the PLC from a remote location? I need the ability to troubleshoot remote PLCs.

Yes both SIM cards are from AT&T prepaid wireless accounts. Both accounts have the data plan activated. I did some more testing using hyperterminal. If I issue the command "ATD14695001234;" the modem will dial the other modem in voice mode. If I issue the command "ATD14695001234" without the semicolon then I get the "no carrier" response. Has anyone had success using the AT&T SIM cards? Is there another US carrier that is known to work such as TMobile?

This SIM is on a prepaid gophone AT&T account. The account is active and has a credit balance. This SIM is open for voice, text and data. There is no separate phone number for data. Do I need to modify the initialization string?

My goal is to use a PC side Enfore modem (GSM-KIT-41J UNITRONICS ENFORE GSM1208 QUAD BAND) to communicate with a PLC side Enfore modem (same exact type) so that I can go online and troubleshoot the program remotely. I have successfully initialized the modem and I can send / receive SMS messages just fine. My problem is that I can not successfully dial the PC modem to make a remote call to the PLC side modem. After I click on the the dial button, I see the dial command go to the modem and the modem replies OK. Then two seconds later, I get a no carrier error and the communication fails. I have read all the help documents I have made sure I am using a serial cable with all the pins wired straight through. I have tried both a desktop PC and laptop PC running windows XP. Both of these PCs have an actual serial port (I am not using a USB to serial converter). The help file mentions an initialization code of S7=30 to give the modem more time, but it doesn't seem to have an effect or I am not entering this command in the inititaliztion string properly. How do I fix my problem?