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IMSTerm Remote Serial / Modem
Support Pages
| Setting
up Serial devices over extended distances: |
The RS232 standard for cable is 30 metres. Line drivers
typically offer up to 1250 metres at 19200 baud (mains powered) or 9600
baud (voltage taken from serial interface). The units used in our test
configuration were Misco 1011 units; an equivalent unit is available from
many sources. The key distinguishing feature is a 25 way D connector one
end, with a 5-way screw terminal block to connect the long distance cable
to.
Configuration: Server end: Moulded 9 to 25 way converters were used to
attach the driver to the 9 way D port offered. This was to ensure a
voltage was available to power the line driver. Because a link was already
in place which was proving to be too long for the serial port to drive, a
converter was soldered together (in this case a 9 way D male with 4
conductors soldered in place, on pins 2,3,5 & 6.) The four connections
on the converter were inserted into the Rx+, Rx-, Tx+ and Tx- connections
on the line driver. In this case the connections were: 2>Rx+ 3>Rx-
5>Tx+ 6>Tx-. The line driver can now be inserted in the cable run
without modification to the existing cable. (The fifth connection,
"protective ground", is offered, but only needed in high
electrical noise environments, according to Misco tech support). Terminal
end: The same configuration procedure was adopted, but this time using
pins 2,3,4 & 5 on the 9 way connector, to link to the existing cable.
This time, however, the four conductors that enter the screw terminal
block need to be connected thus: The connector from Rx+ at the server is
connected to Tx+ at the terminal. Rx- Tx- Tx+ Rx+ Tx- Rx- In our case,
2>Tx- 3>Tx+ 4>Rx- 5>Rx+ were the correct choices. The internal
switches inside the driver cases were left as default, ie on,off,on,off at
both ends, since both serial devices were DTE devices. |
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| Lost
characters when printing |
This is a recurrent report - usually happening after a few
pages of printout. The classic symptom is that a character or characters
will disappear from a line of text, but each subsequent line is fine until
the same thing happens again a few lines further on. The problem is
usually that the characters are being lost by unbufferd uarts - the chips
that control serial port I/O. If your baud rate is greater than 9600,
please ensure you have buffered uarts (types 16450 and 16550) in use. If
you are in doubt, IMSD.EXE will advise you which type of uart is in use.
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| Old copies
of IMSterm.exe |
One or two old copies of IMSTERM.EXE have surfaced recently,
and caused some grief. A very few early REAL/32 copies had a difficulty
which led to either Capslock freezing the emulator or printing being
corrupted via the terminal. Although this was corrected almost
immediately, some of the old copies are still on user sites. The cure is
to run "Xdir IMSTERM.EXE /c /s" from the root directory of a
hard drive, to determine the checksum of all copies of IMSTERM.EXE on that
system. The earliest correct version carries checksum 64FC dated 13/10/95
(timestamp 7.54) - any version older than that should be replaced.
You may download
this version here.
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| IMSterm under
REAL/32. |
Running IMSterm on a REAL/32 server has good implications
for remote maintenance, especially when Remote Windows is launched with
REAL/32 7.6, since that will include file transfer in either direction.
Since both the server and IMSterm use the same task switching keys by
default, you are advised to opt for a different set of switching keys for
IMSterm. Provided you don't plan to use anything other than text screens,
a Wyse terminal will be sufficient to run the IMSterm session to the
remote server! The two difficulties might be screen colours (where colour
differentiation on a mono terminal screen might be a problem), and some
garbage may be placed on the terminal
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| Quick
cable set up for Wyse and C192 Terminals, and PCs running IMSTerm under
Real/32: |
1) The cable connections:-
25 way host to 25 way terminal: 3-2 2-3 6-20 7-7
25 way host to 9 way terminal: 3-3 2-2 6-4 7-5
9 way host to 25 way terminal: 2-2 3-3 6-20 5-7
9 way host to 9 way terminal: 2-3 3-2 6- 4 5-5
Please refer to your Installation manual appendix B for full cabling
instructions.
2) Set the Host flow control to "Transmit DSR = YES". All
other options on this screen to "No".
3) Set the terminal to "DTR" flow control, to match the DSR.
In the case of IMSTerm, select Hard flow control.
Finally: Check the baud rates match at both ends, that Parity is set to
EVEN, Databits are set to 8 and stop bits set to 1. If you have unbuffered
UARTS on your server or PC terminal, be aware of the danger of lost
characters at high baud rates. Your installation should now run smoothly.
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| Quick
set up for IMSTerm Remote with Courier Sportster 14400 modems |
Preparation
Check your IMSTerm.exe is release 5.01, Checksum 64FC. or later.
At the TERMINAL end: Set the IMSTerm flow control to Hardware. The
modem should have switches 3,5,8 set down. Use the following string at the
IMSTerm (PC) end:
AT ATtention
&F load factory settings
E0 Local Echo Off
&B1 Fix baud rate from Modem to Com port
&R2 Set Hardware (RTS) flow control
&W Write the configuration to NVRAM
And the hang up string:
||+++||ATH0
SERVER/HOST setup: Set the flow control to RTS/CTS protocols. On the
server/host modem, set modem switches 3,5,8 down. Use the following string
in the setup program at the server end:
AT ATention
E0 Local Echo Off
&B1 Fix the baud rate from Modem to Com port
&H1 Set hardware (CTS) flow control
&R2 Set Hardware (RTS) flow control
Q2 Suppress result codes in answer mode
S0=1 Answer incoming calls on first ring
&W Write the configuration to NVRAM
And the hang up string:
||+++||ATH0 |
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