does a standalone SPEBlox work with any 1000BaseT1 source to convert it to 1000baseT connection? or it only works with 2 SPEBlox used on either side of the link ?
SPEBlox can be used with any other 1000BASE-T1 device. In other words, it is interoperable with any other device that 1000BASE-T1. Do bear in mind that 1000BASE-T1 requires one device to be the link master, and the other device to be a link slave. You can set slave or master mode on SPEBlox using a solder jumper on the back.
So to your first question, yes you can use SPEBlox to convert from a 1000BASE-T1 source back to a 1000BASE-T link, allowing a 1000BASE-T1 source to work in a 1000BASE-T network. In this way, SPEBlox functions like a transparent bridge, and it supports this operation out-the-box.
To your second question “does it only work when there is a transceiver at both ends?”, I don’t fully understand what you mean. Any 1000BASE-T1 link ultimately requires a 1000BASE-T1 transceiver on both sides. The difference with SPEBlox is that it has both a 1000BASE-T1 and a 1000BASE-T transceiver onboard, so it can achieve the conversion.