signotec signature pads are connected locally at the workstation. If the signing application — for example signoSign/2, signoSign/Universal, Adobe Acrobat with the signotec plug-in, or a custom line-of-business application using the signoPAD API — runs on a terminal server or VDI desktop, the connection between the pad and the application must be bridged across the remote session.
Mechanisms
signotec supports four transport mechanisms for operation on a terminal server:
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Citrix Virtual Channel — a dedicated, compressed channel over the ICA protocol. Requires a licensed signotec driver on the client. Citrix-specific.
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Virtual Serial Connection — the pad is provided on the client as a virtual COM port; this COM port is mapped into the session using built-in Citrix/RDP mechanisms. The USB-to-COM conversion happens either in hardware (devices with an FTDI chip, item number ending in
FT100) or in software (signotec VCOM driver, item number ending inU100). -
USB Redirection — the pad is passed through into the session as a complete USB device: Citrix Generic USB Redirection or the USB redirection feature of the RDP stack (RemoteFX).
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Network Connection — the pad is not connected to the client but is reachable directly via IP on the network. This is possible using the signotec USB-Ethernet adapter (for pads in USB mode, item number
U100) or the signotec Delta with an integrated RJ45 port. In both cases, the pad is client-independent and can also be used sequentially from multiple workstations.
Architecture Overview
From the server application's perspective, the pad looks like a locally connected resource in the first three variants — the difference lies in the transport between client and server. With the Network Connection, the client is not involved at all; the server and pad communicate directly via TCP/IP.
Recommendation
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In Citrix environments the Citrix Virtual Channel is our primary recommendation. The connection is significantly faster and more stable than the other variants. The difference is especially noticeable with pads that have a color display and document preview.
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Where the Virtual Channel is not an option (pure RDP environment, driver deployment not possible, restricted endpoints), the Network Connection is in many cases the second-best option — provided the network infrastructure is suitable and the application supports network mode.
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The virtual serial connection is a proven and widely applicable solution. Performance falls between the network connection and USB redirection; based on our experience and customer feedback, the VCOM variant (
U100) is noticeably faster than native USB redirection. -
The native USB redirection works without a signotec driver, but in practice it is the weakest option. In particular, RDP USB redirection (historically "RemoteFX USB Redirection") is usually unsatisfactory in terms of latency and stability. It is useful as a fallback or for quick testing, but not recommended for production.
For a full comparison of the options, see Comparison of Options.
Notes
This documentation is intended for administrators and describes the technology provided by signotec along with the respective requirements. Suitability in a specific customer environment (Citrix version, Workspace App platform, cloud/on-premises deployment, thin client model) is the administrator's responsibility and should be verified in a test environment before rollout.
Device-related notes — such as connection type, USB Y-cable, power supply, or availability of the FT100 and U100 variants — can be found in the respective pad manual.
On request, signotec is happy to provide support through support services and workshops.