[GreenKeys] ASR33 - help identifying board & purpose

[ian parr]

Hello everyone.

So I'm still working on my ASR33 restoration and have had lots of great help so far.
I'm now trying to connect my unit to my computer with a full duplex (two loops) 20mA current loop connection.

I THINK my unit is actually configured for 60mA half duplex so want to change it.

I have looked at the change guide below:
https://deramp.com/downloads/mfe_archive/030-Terminals/Teletype/Model%2033/Kilobaud%20July%201977%20Inside%20the%20Amazing%20ASR%2033.pdf
deramp.com<https://deramp.com/downloads/mfe_archive/030-Terminals/Teletype/Model%2033/Kilobaud%20July%201977%20Inside%20the%20Amazing%20ASR%2033.pdf>
keep right on typing, but most of them continue on for years as long as liberally supplied with lubricating oil. Service manuals have lengthy
deramp.com

>From reading that article, it does seem my unit is wired for 60mA

BUT I I have this additional module installed and it has a connection to the purple wire on it (which would need to move to terminal 9 on the tagstrip.

Does anyone know what this relay unit of for please ? It has a 'Wallac 2557' marking on the rear/


https://photos.app.goo.gl/Myat1Qkg4U2TRM3x8
[https://lh3.googleusercontent.com/pw/AP1GczNhUSf-KCLaMlvPmpTR2mFtKZB_e7KSaB8PdawpifDvBnj1e3hlE21R8A0A-_dl-LOo7AgucKMRwbnBcK6NNzSpIUPn02G_y44o2udiKHDNdPQjZNeW=w600-h315-p-k]<https://photos.app.goo.gl/Myat1Qkg4U2TRM3x8>
2 new items by Ian Parr<https://photos.app.goo.gl/Myat1Qkg4U2TRM3x8>
photos.app.goo.gl


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